How can I find old (iOS 3.x) apps in iTunes store?

[seattle]

I have an Original iPhone that I still use (I have a 4S as well) and would like to find some new apps in the iTunes store. Is there a way to find apps that will work with iOS 3.x?

 

[zedsar]

If you go on the original iPhone onto the app store, if an app has a compatible version with that phone, it should download when you try to download it