Hah, it's the cheogram app, using a JMP.chat phone number. No SIM in this phone, so have been playing with eSIM (silentlink) and such, to enable calling and texting.
Discussion
(With traditional phone numbers / SMS rather than making people use signal or other apps)
Nice! I've been meaning to try silentlink. maybe i'll find an old android phone somewhere
For a minute I thought you had a way to combine separate apps into one link (folder or something) with olauncher.