Help with SwirlyMMS

Hey so I just opened an account with T-Mobile, and I have iPhone 2G.
Now I have the new swirlyMMS on the iPhone (version 1.2.9) and I need the setting for T-Mobile (I found settings but for a different version.
Oh and is there any way to unlock the application? to work without paying??
Oh and how does it work? with internet connection? or like a regular SMS how people can send me MMS? only making an MMS message and sending it by putting in my number?