Send text messages and have group conversations for free with Yahoo’s messaging app Hub for Android. The app sends text messages over your WIFI or data connection, which means you won’t have to pay text messaging fees (US only).
Free local and international SMS messages to other Hub users
Conversations with several friends at once
Privacy – Add and view friends to any conversation thread
Friends can reply with any SMS enabled phone
Note: For Android 2.1 or higher. Only available for mobile phones with US SIM card and text plan.