From February 2014[28] to February 2017,[101] Signal's official Android client required the proprietary Google Play Services because the app was dependent on Google's GCM push-messaging framework.[102][101] In March 2015, Signal moved to a model of handling the app's message delivery themselves and only using GCM for a wakeup event.[103] In February 2017, Signal's developers implemented WebSocket support into the client, making it possible for it to be used without Google Play Services.[101]
[^] # Re: Signal a l'air très intéressant mais...
Posté par cosmocat . En réponse au lien Adding Encrypted Group Calls to Signal. Évalué à 2.
Peut-être une explication. Source : https://en.m.wikipedia.org/wiki/Signal_(software)