AntennaPod

Free open source podcast player for Android devices. The app lets you listen to podcasts, keep track of episodes and manage your podcast subscriptions through open standards like RSS.

Fediverse account:
@AntennaPod@fosstodon.org

K-9 Mail

Very popular free open source e-mail app for Android. It is due to become the official Thunderbird app for Android devices.

Fediverse address:
@k9mail@fosstodon.org

E Foundation / Murena

The E Foundation develops and maintains a free open source privacy-friendly de-Googled version of Android, which you can either install yourself on your existing phone or buy pre-installed on a new phone. They sell pre-installed phones through the Murena brand, all of which are manufactured by established companies like Fairphone, Samsung etc.

Fediverse address (E Foundation):
@e_mydata@mastodon.social

Fediverse address (Murena):
@murena@mastodon.social

Topio e.V.

German non-profit organisation which helps ordinary people “de-Google” their phones by installing privacy-friendly operating systems. They run events to help with this including workshops, exhibitions, lectures etc.

Fediverse address (main account, in German):
@topio@mastodon.social

Fediverse address (photos, in German):
@topio@pixelfed.social

Fediverse address (events, in German):
@topio_space@mobilize.berlin