I've had an iPod Touch for over five years now, and as a music player, it still works as well as it did when I got it in late 2010.

The trouble is with apps. Every app seems to act very sluggish and then crash (some just crash). The iPod does have appropriate versions for its operating system (maxed out at the highest version of iOS 6).

I have completely reset the iPod, done it from the ground up, and this problem persists. Even something native like the messages app is quite slow. The push notifications come over quickly enough, but replying to an iMessage can take longer than it should.

Any thoughts on what is causing this and how to fix it?