Even if it were technically easy, you would likely have lawyers from the likes of OAG breathing down your neck.

For this reason, I (as the original author) intentionally didn't include any timetable data or flight numbers. The purpose of the app is to show you all possible routes you can fly (it was inspired by OAG Flight Atlas, which is no longer being published). Once you know the route, it should be easy enough to look up timetables for that route.

There are commercial flight databases out there (like OAG, FlightAware etc.), but they will probably want your arm and your leg to use their data.