Signal

Signal is a "private" instant messenger.

Spyware level: MEDIUM

You need to give Signal your phone number to work

You cannot create an account in Signal without giving it your phone number.

Signal is not completly Peer-To-Peer

Signal claims to be a Peer-To-Peer messenger. But this is not true because Signal stores your phone number in the servers.¹

Signal encourages to be downloaded from Google Play

Signal encourages to be downloaded from Google Play. Google play required the "Google Play Services" rootkit. And Signal developers don't want to change this.²

Further reading

Signal considered harmful

References