#Whatsapp alternatives
Surespot, TextSecure and Xabber are !FreeSoftware ("Open Source") SMS/chat/message application. Thanks to Android-User 10/2013.
Evan Prodromou likes this.
There are lots of alternatives in #FDroid too. All of them not only #freesoftware #opensource, but also built from source, and downloadable from a repository you can trust (and being the repository freesoftware itself) :)
In the 'pure XMPP' side: Xabber, Tigase, Chatsecure, Yaxim, Beem, BombusMod
Non XMPP but being refactorized towards XMPP: Kontalk
I've tried myself and use frequently Xabber and Kontalk (2.x,non-XMPP), and now I'm beginning to try ChatSecure.
BTW I like to search and learn why a certain software is not in F-Droid (yet). Interesting comments about SureSpot and TextSecure.