Why won't my apps work?
as soon as i tap on an app icon, the main screen flashes on then off immediately. i can access my music, calendar, calculator,...t
your iPod is kinda out of date, so these days on App store, Apps are built for iOS 4.1 or higher. As iPod 1st gen. doesn't get an update of iOS 4.1 or higher, therefore apps don't run on older platforms of Apple now.
Try to update your iPod to a newer iOS version to get new great Apps.