What happened to Find my iPod on my 2G?

[Mikebike125]

I used to have find my ipod on my 2G ipod touch but now it is telling me that it cannot be loaded because the Find my iPod app is only compatable with iOS5 and you can't put iOS5 on a 2G touch. The find my ipod feature is very important to me and my 9year old. I was running the iOS 4.2.1 and thought that was the problem so I went through the steps to downgrade back to iOS 4.1 but the app still does not work. HELP!!

Why has this stopped working and what can I do to get this going again?

Thanks!