Once you have the app downloaded and on your phone, open the app GOSMS Pro. Click menu and then settings. In settings, click application settings. There should be an option (3 down) called message grouping. Make sure that box is checked. After you do this, it should push all the future group messages into a single thread. I think it only does this if the messages are received with in a certain amount of time of each other, but I'm not certain on that.