iPhone 3G - iOS 4.2.1 - Its not working

It was installed successfully, but when I try to open it, it closes in the splash screen for no apparent reason and with no message. It seems to be a really good program, but unfortunately I couldnt even try it. Hope to find a way to fix it. Maybe you reading this know something. Please apple, reply my inquiry. Thank you!

Guilherme Taffarel Bergamin about EasyTrails GPS Lite, v8.5