Radar Spotter
Not sure if this is already mentioned in last year's thread, but downloaded this app a few weeks ago, but already a favorite of mine: "Radar Spotter".
Start the app and point it at any flight you can see in the sky and it will tell you flight details including route, airline, flightnumber, registration and distance from your current location.
Free version will do all of the above, paid version has some additional features