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?
My main ones right now are OSMAnd + BRouter for maps, Spotube + ListenBrainz for music, Etar and Tasks.org + DAVx5 for calendar/tasks, Cheogram for texts/calls, Bitwarden for passwords/passkeys, F-Droid for downloading apps.