CalyxOS _{Free (open source)}

Everyone needs a phone. Not everyone wants governments and corporations tracking their every move and spying on their communications. CalyxOS lets you have your cake and eat it too, with "Privacy by Design".

To know which devices support CalyxOS check here
Android

GrapheneOS _{Free (open source)}

GrapheneOS is a privacy / security research and engineering project that has been under way for over 5 years. It recently became rebranded as GrapheneOS and is taking a different direction based on obtaining funding for the research and development work as a non-profit open source project rather than being a company.

Prebuilts are provided for the Pixel 4, 4 XL and 4a so this step is optional for those. This will be done for the other devices in the future.

List of kernels corresponding to officially supported devices:

• Pixel 2, Pixel 2 XL: wahoo - separate builds due to hardening
• Pixel 2: taimen
• Pixel 2 XL: walleye
• Pixel 3, Pixel 3 XL, Pixel 3a, Pixel 3a XL: crosshatch - separate builds due to hardening
• Pixel 3: crosshatch
• Pixel 3 XL: blueline
• Pixel 3a, Pixel 3a XL: bonito
• Pixel 4, Pixel 4 XL: coral
• Pixel 4a: sunfish

Android

LineageOS(Official) _{Free (open source)}

A free and open-source operating system for smartphones and tablet computers, based on the Android mobile platform. It is the successor to the highly popular custom ROM CyanogenMod, from which it was forked in December 2016 when Cyanogen Inc. announced it was discontinuing development and shut down the infrastructure behind the project. Since Cyanogen Inc. retained the rights to the Cyanogen name, the project rebranded its fork as LineageOS.

To know which devices support LineageOS check here
Android

Mozilla Firefox _{Free (open source)}

Mozilla Firefox, or simply Firefox, is a free and open-source web browser developed by the Mozilla Foundation and its subsidiary, the Mozilla Corporation. Firefox uses the Gecko layout engine to render web pages, which implements current and anticipated web standards.

Android / Android Tablet / Linux / MacOS / Windows / Iphone / Ipad / Chrome OS

Brave _{Free (open source)}

Brave is a free and open-source web browser developed by Brave Software, Inc. based on the Chromium web browser. It blocks ads and website trackers, and provides a way for users to send cryptocurrency contributions in the form of Basic Attention Tokens to websites and content creators.

Android / Android Tablet / Linux / MacOS / Windows / BSD / Iphone / Ipad

Chromium _{Free (open source)}

Chromium is a free and open-source software project developed by the Google-sponsored Chromium project. The source code can be compiled into a web browser. Google uses the code to make its Chrome browser, which has more features than Chromium.

Android / Android Tablet / Linux / MacOS / Windows / BSD / Iphone / Ipad / Chrome OS

TOR Browser _{Free (open source)}

Tor is free and open-source software for enabling anonymous communication. The name derived from the acronym for the original software project name "The Onion Router". Tor directs Internet traffic through a free, worldwide, volunteer overlay network consisting of more than seven thousand relays to conceal a user's location and usage from anyone conducting network surveillance or traffic analysis.

Android / Android Tablet / Linux / MacOS / Windows / Open BSD
Onion Browser _{Free (open source)}

Surf the web through the Tor network with this open source browser for iOS devices.

Iphone / Ipad

Ungoogled Chromium _{Free (open source)}

Ungoogled-chromium is Google Chromium, sans dependency on Google web services. Ungoogled-chromium retains the default Chromium experience as closely as possible. Unlike other Chromium forks that have their own visions of a web browser, ungoogled-chromium is essentially a drop-in replacement for Chromium. Ungoogled-chromium features tweaks to enhance privacy, control, and transparency. However, almost all of these features must be manually activated or enabled. For more details, see Feature Overview.

Android / Linux / MacOS / Windows

DuckDuckGo Privacy Browser _{Free (open source)}

Tired of being tracked online? We can help. At DuckDuckGo, online privacy should be simple. DuckDuckGo Privacy Browser has the speed you need, the browsing features you expect (like tabs & bookmarks), and comes packed with best-in-class privacy essentials.

Android / Android Tablet / Iphone / Ipad

Bromite _{Free (open source)}

Bromite is a Chromium fork with ad blocking and privacy enhancements; take back your browser! The main goal is to provide a no-clutter browsing experience without privacy-invasive features and with the addition of a fast ad-blocking engine. Minimal UI changes are applied to help curbing the idea of “browser as an advertisement platform”. All patches are published under GNU/GPL v3 to enable other open source projects’ usage. Bromite is only available for Android Lollipop (v5.0, API level 21) and above.

Android

DuckDuckGo _Free

DuckDuckGo is an alternative search engine that has rich features, respects your privacy, and is built from free/open-source software. DuckDuckGo distinguishes itself from other search engines by not profiling its users and by showing all users the same search results for a given search term. Zero-click Info - Useful information above the links. More Privacy - We do not track you. Goodies - Instant answers, !bangs & settings. Less Spam - We remove sites with just ads.

Android / Android Tablet / Iphone / Ipad / Web

Whoogle _{Free (open source)}

Get Google search results, but without any ads, javascript, AMP links, cookies, or IP address tracking. Easily deployable in one click as a Docker app, and customizable with a single config file. Quick and simple to implement as a primary search engine replacement on both desktop and mobile. Whoogle can also be self hosted.

Windows / Web

Startpage _Free

Startpage is a Dutch search engine company that highlights privacy as its distinguishing feature. The website advertises that it allows users to obtain Google Search results while protecting users' privacy by not storing personal information or search data and removing all trackers. Startpage.com also includes an Anonymous View browsing feature that allows users the option to open search results via proxy for increased anonymity. Because the company is based in the Netherlands, it is protected by Dutch and European Union privacy laws, and thus is not subject to United States surveillance programs, like PRISM.

Android / Android Tablet / Iphone / Ipad / Web

searx _{Free (open source)}

Searx is a metasearch engine, aggregating the results of other search engines while not storing information about its users. It provides basic privacy by mixing your queries with searches on other platforms without storing search data. Queries are made using a POST request on every browser (except chrome). Therefore they show up in neither our logs, nor your URL history. In case of Chrome users there is an exception, Searx uses the search bar to perform GET requests. Searx can be added to your browser's search bar; moreover, it can be set as the default search engine. Searx can also be self-hosted.

Android / Linux / Web

Qwant _Free

Qwant is a European web search engine, launched in July 2013 and operated from Paris. It is the only EU-based search engine with its own indexing engine. It claims not to employ user tracking and doesn't personalize search results in order to avoid trapping users in a filter bubble. It is available in 13 languages.

Android / Android Tablet / Iphone / Ipad / Web

MetaGer _{Free (open source)}

MetaGer is a SaaS by the German non-profit SUMA e.V. that provides you with anonymous meta search results.

Android / Web

Search Encrypt _Free

Search Encrypt was designed from the ground up with privacy as its core value. Search Encrypt protects your privacy by encrypting your search terms, expiring your browsing history, and forcing advanced SSL encryption.

Web

F-Droid _{Free (open source)}

The F-Droid Repository is an easily-installable catalogue of free and open source apps for Android. With F-Droid, it's easy to browse and install apps on your device, and keep track of updates. You can also browse the repository with a web browser, and download the app directly from there, if you can’t or don’t want to run the F-Droid client on your device. All applications in the default repository must be Free and Open Source software – for example, released under a GPL or Apache license. Every effort is made to verify that this is actually the case, both by visual inspection of the source, and by building the application from the published source.

Android / Android Tablet / Web

Aurora Store _{Free (open source)}

Aurora Store is an unofficial, FOSS client to Google's Play Store with an elegant design. Not only does Aurora Store download, update, and search for apps like the Play Store, it also empowers the user with new features. For those concerned with privacy, Aurora Store does not require Google's proprietary framework (spyware?) to operate; It works perfectly fine with or without GooglePlayService or MicroG. However, those still reliant on those services are welcome to use Aurora Store as well! While Aurora Store was originally based on Sergei Yeriomin's Yalp store, v3.0 is a clean & complete rewrite from scratch that follows Material Design and runs on all devices running Android 5.0+.

Android / Android Tablet

Aptoide _{Free (open source)}

Aptoide is a distributed marketplace for mobile applications which runs on the Android operating system. In Aptoide, unlike the default Google Play Store, there is not a unique and centralized store but each user manages their own store. Currently, there are several versions of the Aptoide app: Aptoide Mobile and Aptoide Lite for smartphones and tablets, Aptoide TV - an edition for smart TVs and STBs, and Aptoide Kids - developed for children devices. Recently, Aptoide launched a VR App Store. Aptoide also provides B2B solutions, allowing its partners to manage their own app store in an autonomous and customized way. The Android application used to access the stores is open source, and there are several forks such as F-Droid. The communication between the client and servers is done using an open protocol based on XML. The concept is inspired by the APT packaging manager, which can work with multiple sources (repositories). When the user wants a package, they use the client to search for sources where the application is stored. The name Aptoide is formed from the words "APT" (the Debian package manager) and "oide" (the last syllable of "Android"). The Aptoide platform is available in over 40 languages, having reached more than 97 million users in 2015 and 2.8 billion downloads. In the various stores it is possible to find over 700.000 Android apps.

Android / Android Tablet / Web

Aurora Droid _{Free (open source)}

Aurora Droid is an unofficial, FOSS client to FDroid and FDroid-compatible repositories with an elegant design. Not only does Aurora Store download, update, and search for apps like the Official FDroid client, it also empowers the user with new features.

Android / Android Tablet

Nextcloud _{Free (open source)}

A safe home for all your data. Secure, under your control and developed in an open, transparent and trustworthy way. Nextcloud offers industry-leading on-premises file sync and online collaboration technology. Our expertise is in combining the convenience and ease of use of consumer-grade solutions like Dropbox and Google Drive with the security, privacy and control business needs. Nextcloud also allows to self-host data. Self-hosted solutions ensure you know where data is, who has access, and that even meta-data does not leak.

Android / Android Tablet / Linux / MacOS / Windows / Iphone / Ipad / Web

Simple Gallery _{Free (open source)}

Simple Gallery is a highly customizable offline gallery. Organize & edit your photos, recover deleted files with the recycle bin, protect & hide files and view a huge variety of different photo & video formats including RAW, SVG and much more. The app contains no ads and unnecessary permissions. As the app doesn’t require internet access either, your privacy is protected but problem is does not have cloud storage option like google photos.

Android / Android Tablet

Shotwell _{Free (open source)}

Shotwell is an open source photo organizer designed for the GNOME desktop environment. Features: Import photos from folders or from any digital camera supported by gPhoto. Shotwell automatically groups photos taken at the same time. You can also use tags and ratings to organize your photo collection. You can rotate, crop, reduce red-eye, and adjust the exposure, saturation, tint, and temperature of each photo. Publish photos and videos to Facebook, Flickr, Picasa Web Albums, and YouTube.

Linux

Operationtulip _{Free (open source)}

Operationtulip is a fork of Nextcloud. Operationtulip.com is based in Sweden and is open for public beta now. They provide fair, libre and affordable online storage with additional services. On operation tulip you can not only store your files, you can also check your email, manage your calendar, store your passwords on a secure end-to-end encryption platform, handle contacts, back-up photos and of course - keep your files readily at hand whenever on-line. It uses nextcloud app to manage these.

Android / Android Tablet / Linux / MacOS / Windows / Iphone / Ipad / Web

Nextcloud _{Free (open source)}

A safe home for all your data. Secure, under your control and developed in an open, transparent and trustworthy way. Nextcloud offers industry-leading on-premises file sync and online collaboration technology. Our expertise is in combining the convenience and ease of use of consumer-grade solutions like Dropbox and Google Drive with the security, privacy and control business needs. Nextcloud also allows to self-host data. Self-hosted solutions ensure you know where data is, who has access, and that even meta-data does not leak.

Android / Android Tablet / Linux / MacOS / Windows / Iphone / Ipad / Web

MEGA _Freemium

MEGA, the successor of Small MegaUpload iconMegaUpload , is a cloud storage and file hosting service produced by Mega Limited. This cloud-storage solution claims to protect your privacy with end-to-end encryption and offers a "Secure Collaboration" feature.

Android / Android Tablet / Linux / MacOS / Windows / Iphone / Ipad / Web / ChromeOS

ownCloud _{Freemium (open source)}

Store your private pictures, documents, calendar and contacts on your ownCloud server at home, a rented VPS or use one of the public ownCloud providers. Access your existing data on an FTP drive at work, images shared with you on Dropbox, or your NAS at home--all through your ownCloud server.Run your ownCloud server in a place you trust and access all the data you care about in one place!

Android / Android Tablet / Linux / MacOS / Windows / Iphone / Ipad / Raspberry Pi

Seafile _{Freemium (open source)}

Seafile is a file hosting software system. Files are stored on a central server and can by synchronized with personal computers and mobile devices via the Seafile client. Files can also be accessed via the server's web interface. Seafile's functionality is similar to other popular services such as Dropbox and Google Drive, with the primary difference being that Seafile is free and open-source, enabling users to host their own Seafile servers without artificially imposed limits on storage space or client connections. You can deploy Seafile on your own server for free using the Community Edition, which is opensource, or choose the Professional Edition, that is free for 3 users and has a yearly subscription for more users.

Android / Android Tablet / Linux / MacOS / Windows / Iphone / Ipad

SparkleShare _{Free (open source)}

SparkleShare is a Free Open Source syncing tool. Its light, secure and easy to use. SparkleShare allows you to setup your own servers so you always keep control on your data. SparkleShare was made to cover certain use cases, but doesn't handle every scenario well. To help you decide if SparkleShare is right for you, here's a few examples of what it does well and less well with smiley faces:
Great:

• Frequently changing project files, like text, office documents, and images
• Tracking and syncing files edited by multiple people
• Reverting a file to any point in its history
• Preventing spying on your files on the server using encryption

Not so great:

• Full computer backups
• Large binary files that change often, like video editing projects

Linux / MacOS / Windows

andOTP _{Free (open source)}

andOTP is a two-factor authentication App for Android 5.1+. It implements Time-based One-time Passwords (TOTP) and HMAC-Based One-Time Passwords (HOTP). Simply scan the QR code and login with the generated 6-digit code.

Android / Android Tablet

Aegis Authenticator _{Free (open source)}

Aegis Authenticator is a free, secure and open source app to manage your 2-step verification tokens for your online services. All of your one-time passwords are stored in a vault. If you choose to set a password, which is highly recommended, the vault will be encrypted using AES-256. If someone with malicious intent gets a hold of the vault file, it’s impossible for them to retrieve the contents without knowing the password. Entering your password each time you need access to a one-time password can be cumbersome. Fortunately, you can also enable fingerprint unlock if your device has a fingerprint scanner.

Android

Tofu Authenticator _{Free (open source)}

Tofu generates one-time passwords to help you protect your online accounts. These passwords are used together with your normal password when you sign into services like Google, Facebook, Dropbox, Amazon, and GitHub. Tofu works with all services that provide two-factor authentication using the HOTP and TOTP algorithms. It does not require a network or cellular connection and can be used in airplane mode.

Iphone / Ipad

FreeOTP+ (fork of FreeOTP) _{Free (open source)}

The free and open-sourced Authenticator replacement for 2FA in popular services. This is based on the original FreeOTP. It provides additional features like Back up the data to Google Drive or other storage, Restore data from Google Drive or other storage, Material design and updated UI, Android 6.0 on-demand permission support, Android 6.0 backup support. After reinstalling, all your saved authentications will come back.

Android

Gnome Authenticator _{Free (open source)}

Two-factor authentication application built for GNOME. Features of this app are QR code scanner, beautiful UI, huge database of more than 560 supported services, keep your PIN tokens secure by locking the application with a password, automatically fetch an image for services using their favicon, the possibility to add new services.

Linux

Authenticator _{Free (open source)}

Authenticator generates two-factor authentication (2FA) codes in your browser. Use it to add an extra layer of security to your online accounts. Features: Add accounts by scanning QR codes, Search your accounts by pressing "/", Translated into more than ten languages, Encrypt your secrets with a password, Backup your secrets to a file, Google Drive, or Dropbox Sync your secrets with your Firefox Account, Open source,

Linux(Browser Extension) / MacOS(Browser Extension) / Windows(Browser Extension)

ProtonMail _{Freemium (open source)}

Secure email with absolutely no compromises, brought to you by MIT and CERN scientists. ProtonMail is incorporated in Switzerland and our servers are located in Switzerland. All user data is protected by strict Swiss privacy laws. Because of end-to-end encryption, data is already encrypted by the time it reaches servers. They have no access to your messages, and since they cannot decrypt them, they cannot share them with third parties. They do not log IP addresses or require any personal information to sign up. They accept bitcoin and cash payments for paid accounts to ensure even paid account users have complete privacy.

Android / Iphone / Ipad/ Web

Tutanota _{Freemium (open source)}

Tutanota is a free and open source web-mail client that focuses on privacy and security. It has open source iOS and an Android apps. The Android app is published on F-Droid (which means the app does not use Google's push notification system) making it a great option if you want to de-Google your life. All data is stored encrypted and can not be searched, i.e. for commercial use. It offers dead easy end-to-end encryption. 1 GB of storage is free for everyone.

Android / Iphone / Ipad/ Web

Disroot _{Free (open source)}

Disroot is a platform that offers federated web services to the public. It combines free encrypted email with secure cloud services, including an online office suite. Services provided:

• Email - Rainloop
• Cloud - Nextcloud
• Social Network - Diaspora
• Forum - Discourse
• Chat - XMPP
• Documents - Etherpad
• Spreadsheets - EtherCalc
• Paste Bin - PrivateBin
• File Upload - Lufi
• Search Engine - searx
• Polls - Framadate
• Project Board -Taiga.io

Web

mailbox.org _{Commercial (open source)}

Tutanota is a free and open source web-mail client that focuses on privacy and security. It has open source iOS and an Android apps. The Android app is published on F-Droid (which means the app does not use Google's push notification system) making it a great option if you want to de-Google your life. All data is stored encrypted and can not be searched, i.e. for commercial use. It offers dead easy end-to-end encryption. 1 GB of storage is free for everyone.

Web

PeerTube _{Free (open source)}

PeerTube is a free and open-source, decentralized, federated video platform powered by ActivityPub and WebTorrent, that uses peer-to-peer technology to reduce load on individual servers when viewing videos. Started in 2015 by a programmer known as Chocobozzz, development of PeerTube is now supported by the French non-profit Framasoft. The aim is to provide an alternative to centralized platforms such as YouTube, Vimeo, and Dailymotion.

Web

NewPipe _{Free (open source)}

NewPipe has been created with the purpose of getting the original YouTube experience on your smartphone without annoying ads and questionable permissions. It is available in the F-Droid software repository, in NewPipe's F-Droid repository, or in the GitHub releases page and is only available for Android devices.

Android / Android Tablet

Invidious _{Free (open source)}

An alternative front-end to YouTube. The instance at invidio.us made by Omar Roth was closed in September 2020. You can select another instance and the project can still be found on GitHub.

Web

FreeTube _{Free (open source)}

FreeTube is an open source desktop YouTube player built with privacy in mind. Use YouTube without advertisments and prevent Google tracking from you with their cookies and JavaScript. Available for Windows, Mac & Linux thanks to Electron.

Linux / MacOS / Windows

Yotter _{Free (open source)}

Yotter allows you to follow and gather all the content from your favorite Twitter and YouTube accounts in a beautiful feed so you can stay up to date without compromising your privacy at all. Yotter is written with Python and Flask and uses Semantic-UI as its CSS framework.

Web

DTube _{Free (open source)}

DTube is the first crypto-decentralized video platform.

Web

LBRY _{Free (open source)}

LBRY is the first digital marketplace to be controlled by the market's participants rather than a corporation or other 3rd-party. It is the most open, fair, and efficient marketplace for digital goods ever created, with an incentive design encouraging it to become the most complete.

Android / Android Tablet / Linux / MacOS / Windows / Iphone / Ipad / Web

Etar _{Free (open source)}

Etar is an enhanced version of AOSP Calendar.It has Material design and supports Agenda widget, Dark theme. Uses Android calendar sync. Works with Google Calendar, Exchange, Etesync etc.

Android / Android Tablet

Lightning Calendar _{Free (open source)}

Organize your schedule and life’s important events in a calendar that’s fully integrated with your Thunderbird or Seamonkey email. Manage multiple calendars, create your daily to do list, invite friends to events, and subscribe to public calendars. Lightning brings the Sunbird (Sunbird is discontinued) calendar to the popular email client, Thunderbird and the Small SeaMonkey iconSeaMonkey internet application suite. Since its an extension, Lightning is tightly integrated with Thunderbird or SeaMonkey, allowing it to easily perform email-related calendaring tasks.

Linux / MacOS / Windows

Simple Calendar _{Free (open source)}

A simple calendar with optional CalDAV synchronization. You can easily create recurring events and setup reminders, it can also display week numbers. Contains a monthly view and an event list widget where you can customize the color of the text, as well as the alpha and the color of the background. Contains no ads or unnecessary permissions. It is fully opensource, provides customizable colors. The Storage permission is needed only for exporting or importing events from .ics files. The Contacts permission is used only at importing contact birthdays and anniversaries. This app is just one piece of a bigger series of apps.

Android / Android Tablet

Kontact - KOrganizer _{Free (open source)}

It provides management of events and tasks, alarm notification, web export, network transparent handling of data, group scheduling, import and export of calendar files and more. It is able to work together with a wide variety of calendaring services, including NextCloud, Kolab, Google Calendar and others. KOrganizer is fully customizable to your needs and is an integral part of the Kontact suite, which aims to be a complete solution for organizing your personal data. KOrganizer supports the two dominant standards for storing and exchanging calendar data, vCalendar and iCalendar.

Linux

GNOME Calendar _{Free (open source)}

- All about simplicity
The perfect balance between nicely crafted features and user-centred usability. No excess, no lacks. You'll feel comfortable using Calendar, like you've been using it for ages!
- Beautiful by design
By having a close relation with the team of design experts, GNOME Calendar grew the right way, with it's rough edges being polished right after they appear, making the pixel-perfect calendar application.

Linux

QKSMS _{Free (open source)}

QKSMS brings a refreshingly beautiful and responsive Material Design touch to the stale state of text messaging. In a world with clunky SMS and MMS apps cluttered with bloat and ads, QKSMS is something to get excited about. QKSMS is also fully open source!

Android / Android Tablet

Simple SMS Messenger _{Free (open source)}

A great way to stay in touch with your relatives, by sending both SMS and MMS messages. The app properly handles group messaging too, just like blocking numbers from Android 7+. It offers many date formats to choose from, to make you feel comfortable at using it. You can toggle between 12 and 24 hours time format too. It has a really tiny app size compared to the competition, making it really fast to download The internet access is sadly required for sending MMS attachments. Not being able to send MMS would be a really huge disadvantage compared to other apps, so we decided to go this way. However, as usually, there are no ads, tracking or analytics whatsoever, the internet is used only for sending MMS. It comes with material design and dark theme by default, provides great user experience for easy usage. Contains no ads or unnecessary permissions. It is fully opensource, provides customizable colors.

Android / Android Tablet

Silence _{Free (open source)}

Protect your communication in transit and on your phone. Silence is a full replacement for the default text messaging application: all messages are encrypted locally and messages to other Silence users are encrypted over the air. Interesting and open-source Android apps, Open Source Android Apps, Liberate your Android, Android Apps for Privacy and Security, and Without Microsoft, Google, Facebook, Apple & etc.

Android

Jitsi Meet _{Free (open source)}

Go ahead, video chat with the whole team. In fact, invite everyone you know. Jitsi Meet is a fully encrypted, 100% open source video conferencing solution that you can use all day, every day, for free — with no account needed.

Android / Android Tablet / Iphone / Ipad / Web

Jami _{Free (open source)}

An official GNU package, Jami is licensed under the GPLv3, and takes its commitments to security and free and open source software very seriously. Communications are secured by end-to-end encryption with authentication using RSA/AES/DTLS/SRTP technologies and X.509 certificates. You can communicate using either a unique user ID (which the Jami app randomly generates the first time it's launched) or over SIP. You can use your ID and SIP in parallel, switching between protocols as needed, but you must register your ID on the blockchain before it can be used to make or receive communications. Jami's features include teleconferencing, media sharing, and text messaging.

Android / Android Tablet / Linux / MacOS / Windows / Iphone / Ipad

Signal _{Free (open source)}

If you're looking for a simple and secure messaging app for phones, you can't go wrong with Signal. It has been around for years, and not only are both the mobile apps and server software open-source, but Signal has also passed several security audits with flying colors. No accounts or complicated setup processes are necessary: just download the app, put in your phone number, and you're done. You can optionally set it as your phone's SMS application, and when you go to text someone, the message will be sent over Signal if the other person has the app set up (similar to how iMessage works).

Android / Android Tablet / Linux / MacOS / Windows / Iphone

Element _{Freemium (open source)}

If you're more in the market for something like Slack and Discord, you should try Element. Element uses the somewhat-new Matrix protocol, which gives you access to a network of independently-operated servers, each with their own collection of rooms. It's sort of like how email works — you can create an account on one server, and then use that account to send and receive messages from any other Matrix server. It's completely de-centralized and open-source.

Android / Android Tablet / Linux / MacOS / Windows / Iphone / Ipad / Web

Wire _{Freemium (open source)}

Wire is the most secure collaboration platform featuring messenger, voice, video, conference calls, file-sharing, and external collaboration –all protected by the most secure end-to-end-encryption.
Why Wire?
- Always-on end-to-end encryption
- 1:1 and group messaging
- Voice call
- Video conference
- Screen-sharing
- File-sharing
- Searchable conversations
- Guest Rooms (external collaboration)
- Advanced team management
- iOS, Android & Desktop support
- Available on desktop, mobile, and web app
- Synced in real-time across all devices

Android / Android Tablet / Linux / MacOS / Windows / Iphone / Ipad / Web

LibreOffice _{Free (open source)}

LibreOffice is a free and open-source office suite that is compatible with other major office suites, and is available on all operating systems. It is an independently-developed version of the OpenOffice.org suite.

Linux / MacOS / Windows / BSD

Apache OpenOffice _{Freemium (open source)}

Apache OpenOffice is a leading open-source office suite that offers free applications for word processing, spreadsheet, presentations, graphics, databases and more. All data is stored in an open standard format, though Open Office can also read and write files from other common office software.

Linux / MacOS / Windows / BSD

ONLYOFFICE _{Freemium (open source)}

OnlyOffice, stylized as ONLYOFFICE, is a free software office suite developed by Ascensio System SIA, a company headquartered in Riga, Latvia. It features online document editors, platform for document management, corporate communication, mail and project management tools.

Android / Android Tablet / Linux / MacOS / Windows / Iphone / Ipad / Web

Calligra Suite _{Free (open source)}

Calligra Suite is a graphic art and office suite by KDE. It is available for desktop PCs, tablet computers, and smartphones. It contains applications for word processing, spreadsheets, presentation, databases, vector graphics, and digital painting.

Linux / MacOS / Windows / BSD

Collabora Office _{Commercial (open source)}

Collabora Office is the enterprise-ready version of the world’s most widely used Open Source office suite – LibreOffice. Backed by a global community of developers, testers, and localization specialists, Collabora Office is built for critical business needs and discerning users by Collabora - the world's leading LibreOffice services company.

Android / Android Tablet / Linux / MacOS / Windows / Iphone / Ipad / Web