It’s certainly happened at least once that your flight has been delayed or you were waiting someone at the airport and his flight was on delay, now you’d know that you can check the flights’ route.
With the app Flightradar24 you can see in real time where is the flight. You can filter your search with your flight number, airplane company and city of departure and landing, obviously you need only a internet connection.
It’s available as free app and paid version for IOS, Android and desktop.
There are a various websites and apps with similar services, I’m feeling really good with this one but if you don’t like it try something else and, if you like, give me your feedback on similar apps.