SyncThing - to sync my files between devices and avoid the big corporations cloud (use it for notes, Keepass database, photos, etc)
Logseq - super advanced note taking with tagging and relationships between notes (all store locally)
Authpass - opening my Keepass password database on my phone
GrapheneOS Camera - just to avoid the Google camera app as I have Google Photos disabled on my phone and needrd a good app that doesn’t break when going to view the gallery (since it tries to open Google Photos)
Simple Gallery - to view my photos on my phone
Signal - I have it but I have very few friends that use it unfortunately
AntennaPod - for podcasts, I’m thinking of self hosting a podcast tracker to sync my listening habits across my devices, we’ll see if that happens
Vinyl Music Player - to play my local mp3 files and playlists (I use MusicBee to manage what I sync to the phone as my mp3 library is quite large, and SyncThing to actually copy stuff over)