If the apps on your iPod aren’t opening, or will start to open and then just disappear, it could be because you don’t have enough memory or there is an issue with the app. The first thing to do is to double tap the Home button and close all the apps that are running in the background and try to open the app again. If the app still won’t start, restart your iPod by holding both the Power and Home buttons down until the Apple logo appears. Try to open the app again after the iPod has completely started back up.
If the iPod app still won’t start, check to make sure you have at least 3GB of free memory on your iPod. You can do this by going to iTunes, clicking on Device, choosing your iPod and then scrolling all the way down to see how much space you have. If you don’t have enough space left, you may need to delete some pictures, videos and songs from your iPod until you have enough memory for your iPod to operate successfully.
If nothing else works and your iPod Apps still won’t open, hold down the app icon until it starts to shake and then delete the app from your iPod. You can then reinstall the app and its best if you install it through iTunes and then sync it back onto your iPod. Finally, if that fails, contact the maker of the App and see if there are any issues that need to be corrected in the app itself.