The apps informs about the points of interest in the route.
The app has a database of flight routes in the continental United States.
After entering your departure and arrival points, you choose the flight path and say when you are taking off. Then the app will estimate the arrival time, show your plane in its built-in map and give you information about the points of interest near you.
However, there may be problems of accuracy. The creator of WindowSeat says that “one of the app’s core features is the dialogue between it and the user.
In this way, a user can make the flight prediction even more accurate by using their own observations as well as information they gather from the cabin staff.”
Source: Runway Girl