Go to your phone homescreen and look at the app dock (the bottom row that contains some apps and stays the same when you switch pages).
Which are yours? Any FOSS apps?
In my case, they are FDroid, Signal, Threema, Firefox and the defaul Samsung camera app. So, 80% FOSS…
Signal ✅
Whatsapp (for those who don’t use signal i must contact) ❌
Firefox ✅ (Which essentially serves as a webapp for an institutional website i need to always visit)
Simplenote ✅
Fennec ✅ (Main browser)