Simplex Chat for messaging!

https://github.com/simplex-chat/simplex-chat

also Robosats for kyc free corn

https://github.com/RoboSats/robosats

and Amethyst for nostr

https://github.com/vitorpamplona/amethyst

Protonmail if you use them for email: https://github.com/ProtonMail/proton-mail-android

element for company / organisation comms using matrix protocol

https://github.com/vector-im/element-android

VLC for media (kudos for not using Microsoft github):
https://code.videolan.org/videolan/vlc-android