Don't like Hangouts for whatever reason? Hate WhatsApp or anything like it? (Kik, iMessage, Facebook Chat, BBM, WeChat, etc. etc.)
Personally, I hate the fact that none of these are truly cross-platform and that they can't talk to each other. Some of them might be secure, but others definitely aren't, and figuring out who's using what is a crapshoot.
So there's good 'ol XMPP (what most of these were probably based on). Linked below are detailed instructions to get set up on DukGo. Use it on whatever XMPP client you can get your hands on - Pidgin (https://www.pidgin.im/download/
) is great for Desktop, Xabber (https://play.google.com/store/apps/details?id=com.xabber.android
) and ChatSecure (https://play.google.com/store/apps/details?id=info.guardianproject.otr.app.im
) for Android, and ChatSecure (https://itunes.apple.com/us/app/chatsecure-encrypted-secure/id464200063?mt=8
) for iOS. If someone can let me know what's available for BlackBerry, that'd be great, but I'm sure there has to be something by now.
I'm there, so you can add me (using my usual Interwebs handle - send a carrier pidgin if you can't figure out what that is).