105
Nothing's iMessage solution might not be as secure as we thought
(www.androidpolice.com)
This is a most excellent place for technology news and articles.
Beeper is pretty good with it, as they make it clear that it's insecure and use an encrypted protocol to get the messages to the server. Still, it's better to host your own (which Beeper lets you do, as it's just Matrix) or not use it.