> Are there any good secure messengers out there that truly works cross platform (iOS, Android and Web/Win/OSX)? It's a shame that something like Telegram seems to be the best right now, considering its dodgy security model.

XMPP+OTR has been supported on major platforms for years (and for decades without OTR). It offers all the features the above Telegram/TextSecure/etc offer, and is descentralized, so you don't rely on some arbitrary third-party.