I'm going to be flying the United Island Hopper. I always enjoy watching the inflight map on my iPad using Flight Radar24 or the United App, but that won't be an option.

Is there an app with downloadable offline maps that will trace my route, using GPS to track my location, just like an inflight map does? It would show my route from the begining point to my current location. I know Google Maps and Apple Maps have Offline Maps, but neither will trace our route as far as I know.
Note: I have a reliable GPS receiver to bluetooth to my iPad, so GPS won't be an issue.