Pretty decent for Track Days

I use this program on a iPad mounted in my car. It works like most GPS speedometers you can get from the iStore however this one has a few other features.....
A G-meter is great when im on the track (not so useful on the road)
Its got max and min speed, a "HUD" so you dont have to keep looking at your speedometer (no need to take the eye off the road)
If you have a data plan on your iPad then you can also use it like any GPS program.
Mainly I use it at the track with the G-meter, if I hit a certain G I know Im about to spin out :)

Siyx about GPSSpeed HD: The GPS tool, v1.1