I've read that the T-Mobile version does not have a physical FM tuner, but I have also read that is does and that its just disable in software, so I just don't know what to believe.
There is a very slim chance then that your phone will work with my ScreenFree FM Radio app ScreenFree FM Radio
but it might be worth a try. I'd be interested in the results either way.
What is the actual model number of your phone?