Been using a degoogled LineageOS phone with all apps being exclusively FLOSS. My favourite free alternatives to proprietary apps and services must be Lemmy (Jerboa) for Reddit, ArcaneChat and Matrix (Extera) for Telegram, Fluxer for Discord.
Which ones are your favourite?
Almost everything I use is FLOSS, with some exceptions that can’t be helped.
System:
Droid-ify, Bitwarden, Termux, Ente Auth, Fossify (File Manager, Clock, Voice Recorder, and Gallery), Proton (Mail, Calendar, VPN, Drive), CalcYou, KDE Connect, Tailscale, Offline Translator, Rain (Weather), Brave, Vanadium, Tor, Addy.io (email aliasing)
Media-Based:
Notesnook, Librera FD (e-reader), Collabora Office, OSS File Scanner, Image Toolbox, Ente Photos, WizeStream (YouTube, PeerTube, and SoundCloud client), MetroList (YouTube Music), Jellyfin, Libre Librivox Listener (audio books), Audire (Shazam client), Auxio (local music player)
Social:
Signal, Element X (Matrix), Cheogram, Mastodon, Interstellar (Piefed), Red Reader (Reddit), Slim Social (Facebook)