The Briar Project is an encrypted FOSS peer-to-peer messenger app which can be used online through @torproject or offline locally through wifi or bluetooth. The "not yet official" Fediverse account for Briar is at:

➡️ @briar

Its offline mode means it can be used locally even if the internet is shut down (for example due to disasters or other reasons).

Briar's website is at briarproject.org

Hyperspace is a free open source Mastodon desktop app for Linux, Mac and Windows. You can follow at:

➡️ @hyperspacedev

The developers are also working on a mobile version called Starlight.

You can get the client or find out more from the Hyperspace website at hyperspace.marquiskurt.net

Kiwix is a free open source app that lets you view and search Wikipedia, other wikis and reference sites like StackExchange entirely offline. You can follow at:

➡️ @kiwix

The app is available for Android, iPhone, Linux, Mac and Windows from the official site at kiwix.org

It's also available via

It's really useful if you are temporarily or permanently without a reliable internet connection.

OnlyOffice is a free open source online office suite. You can follow them at:

➡️ @ONLYOFFICE

There's a paid-for hosting service, or you can host it yourself free. More info is at the official site at onlyoffice.com

Blender is a free open source software suite for creating 3D and 2D CGI animation, stills and effects. You can follow their official Mastodon account at:

➡️ @Blender

They also have an official PeerTube account at:

➡️ @blender

The official website is at blender.org

Darktable is a free open source photography app which lets you organise, view and develop raw image files, like a libre alternative to Adobe Lightroom. You can follow their official account at:

➡️ @darktable

It's available for Linux, Mac and Windows from the official site at darktable.org

Mercury is a new Mastodon app for iPhones. You can follow at:

➡️ @mercury

It's available on the App Store, and the official site is at onmercury.app

It has some interesting features like being able to save hashtags, and apparently it is also particularly good for accessibility 👍

(Thank you to @weirdwriter for the recommendation!)

Joplin is a free open source note taking and to-do app which you can sync online. You can follow at:

➡️ @joplinapp

It's available for Android, iOS, Linux, Mac and Windows from joplinapp.org

Joplin is compatible with a number of syncing services including @nextcloud

Toot! is a Mastodon app for iPhones and iPads, you can follow the official account at:

➡️ @tootapp

The app itself is available from the App Store on your device at apps.apple.com/app/toot/id1229

K-9 Mail is a free open source e-mail app for Android. You can follow the official account at:

➡️ @k9mail

The official site is at k9mail.app

It's available from @fdroidorg and Google Play.

Exodus Privacy is a really useful service which gives privacy reports on Android apps, listing trackers embedded in each app, and permissions each app seeks.

You can follow the official account at:

➡️ @exodus

The service is available on the website at exodus-privacy.eu.org

F-Droid is a free open source alternative to Google Play. It's like an app store, but only has FOSS apps. You can follow at:

➡️ @fdroidorg

You can download F-Droid for Android from the official site at f-droid.org

Mastodon

This is a brand new server run by the main developers of the project as a spin-off of mastodon.social 🐘 It is not focused on any particular niche interest - everyone is welcome as long as you follow our code of conduct!