"Missed any? Shoot me a message on Twitter: @bitario"
I don't have a Twitter account, but if the author happens to be reading this (or if anyone wants to shoot a message to him), I use Threema for secure messaging. I love it. But I admit to not having used the others so I can't comment on how it ranks against the competition.
https://threema.ch/en https://play.google.com/store/apps/details?id=ch.threema.app...