It works pretty well on an Incredible running MUIU-184.108.40.206. I'm very happy to have it. But it's a bit raw, compared to the HTC Sense FM radio.
After scanning and choosing a particlar station, I couldn't find a way to assign the call letters to that frequency. While showing the list, Menu will give an option for New, but if you a frequency and then the name, it complains that "frequency already exist (sic)", since it was found to belocally valid by a Scan.