I came across this thread while looking for a solution, but all that was suggested is using other group chat like apps, that involve using data, and requiring the other parties involved to download a specific app.
Do any of u guys know how to send a group MMS/SMS and have all of the responses show up in the same thread? I know that it is possible to send a group MMS by adding a period in the subject and sending it to multiple people, but the replies do not show up in the same thread; they show up in the individual responders threads. I know that it is possible since it works very well on the iPhone, so I was just hoping that it is also possible on Android and maybe I just haven't figured it out yet. IMO, it's an awesome feature, and seems like a simple feature to implement (I'm just guessing here as I have an almost non-existent knowledge of Android SMS/MMS protocols).