Aegis - an authenticator app.
CoMaps - like Google or apple maps
ConnectBot - let's me ssh into my PC and laptop from my phone, that's nice for me if I just need to do something quick and am in another room.
FluffyChat - this is the matrix client I prefer, other than sending video, that sucks with this one.
Léon - this cleans up URLs to remove the tracking stuff.
Seal - this downloads videos or audio files. I use it because I like to download videos i send people, instead of just sending them a link.
Shelter - this clones apps to a work profile on your phone, which somewhat limits what those apps have access to from your standard profile.