Shen Ji Pan has StarTracker HD (iTunes Link) for the iPad in the iTunes App Store for FREE ($3.99 value) for a limited time.

This is a Star Gazing application which will guide you to recognize all the bright stars in the night sky! Just hold up and point the phone at the sky to see what stars, constellations and deep sky objects you are looking at in realtime. Full utilization of the build-in gyroscope, digital compass and accelerometer drive the best user experience.

With the cutting edge signal processing technique, gyroscope and the raw data directly from the build-in digital compass chip instead of the existing degree provided by Core Location API, this app has a super reaction speed and high accuracy, you must try it out and see how fast it is 😉