"Here you'll find reviews and research about services and how they affect your #privacy both in person and online backed by real world findings and data collected from testing"
Some apps analysed include: 
馃弳 @simplex ( @threemaapp seems to be an undisputed winner on other lists)
馃 @briar
馃 @cwtch
https://privacyspreadsheet.com/messaging-apps
EDIT: this info is controversial (see comments)
#matrix #telegram #xmpp #signal #whatsapp #threema #wire #zoom #CWTCH