Consider #SimplexChat as a privacy messenger and keep Signal as a backup.
Proton privacy and e2e applies to intra domain use. Interacting with other domains is a different matter.
#OrganicMaps works fine and you can complete it with #StreetComplete.
#Syncthing for synchronization, avoid clouds unless selfhosting (and maybe Proton)
#Aegis is a wonderful 2fa app
Thanks to all who develop and help with development of #FOSS