why are my application quitting in the middle of launch

First thing to try is re-starting your iPod.

Press and hold both the Sleep/Wake and the Home buttons for at least ten soeconds. The Apple logo should briefly display and then the iPod will re-start, although it can take several minutes to complete this.

If not successful try the remaining items of:

iOS: Troubleshooting applications purchased from the App Store

Contact the developer/go to their support site

Restore from backup. See:

iOS: How to back up

Restore to factory settings/new iPod