Last Updated: August 27th, 2012
The Android Market certainly doesn't have a lack of group chat-messaging clients, but it appears that Yahoo is ready to throw its hat into the ring away. Separate from the Messenger app (which has been available on Android for quite some time), Hub uses text messages over a data connection - meaning that you won't incur any text messaging charges from using it. Unfortunately, your friends who don't have the client installed will, and in fact they may not be able to use it at all.
Last Updated: August 20th, 2012
While most Android users don't likely spend a lot of time thinking about what's going on in RIM's land of Blackberry, it has been revealed that one of the popular smartphones' mainstay features, Blackberry Messenger, will be coming to Android and iOS. The popular chat service known for its speed, conversation threads, and easy PIN contact transfer will most likely arrive later this year.
Up to this point, Blackberry Messenger has been a closed service, only available on Blackberry phones.