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

Further reading

Signal considered harmful

References