Works well on the HTC Wildfire. I like it because it works, just using voice instructions with the screen off or with other apps in the foreground. It has a host of options to adjust for individual requirements.
What can I say, BRILLIANT! Warns of all mobile and fixed cameras including average speed cameras, is very accurate and will work in conjunction with an iPhone navigation app. Weekly database updates are prompted as you launch the app on the iPhone and downloading new data is quick and efficient over WiFi or 3G.