I do have an &quot;invite&quot; prompt on my SMS contacts that don&#x27;t yet have Signal: &quot;Invite to Signal: Take your conversation with %s to the next level.&quot;. Perhaps it&#x27;s a function in the beta version that isn&#x27;t in the live version yet?<p>I haven&#x27;t seen a message with a double-tick that&#x27;s been dropped <i>yet</i>, at least not on a recent version. It can sometimes behave poorly with Android battery-saving mode - however, so does plain SMS. Turning off sync is part of the actual point of battery-saving, but conversely, I <i>never</i> want to not get messages. That&#x27;s arguably Android&#x27;s problem, not Signal&#x27;s. Still, it uses GCM, so at least there&#x27;s hope for the deep sleep (which I haven&#x27;t tried yet).