I have successfully downloaded the DGI go4 app to an iPad mini, and have been running the Mavic on it for the past week.

I tried to download the same DGI go4 app to my other mini iPad, and I keep getting a message saying that it is not compatible with my device .

These are essentially the same iPads, so I'm not sure why this is occurring?

Any ideas to resolve this?

Are you maybe running an older version of iOS on the second iPad? If so, that's most likely the reason you can't install it there.