No limit (phone may have limit; see FAQ. E.g. some telephone companies may only allow 10 texts). Users have reported sending over 750 in one go!
Uses your Gmail contacts and groups. History. Multiple account support. Group edit (via GroupManager). Name substitution using "$firstname", "$lastname" and "$fullname". Schedule messages: send a message later (Note that this new function is in Beta).
This app cannot be saved to the SD card due to an Android feature to allow it to Send Later.