Testing incoming calls in such private and secure messenger apps as BOTIM, AnyTalk, twinme & Threema on Samsung Galaxy A52. This phone currwntly runs One UI 3.1 on top of Android 11.
In this video:
00:00 BOTIM
00:47 AnyTalk Messenger
01:31 twinme private messenger
02:09 Threema Secure & Private Messenger