Ability to log spotted flights on app

Just an idea of a feature they could possibly add to the app. The ability to log the flights that you have physically seen.
i.e. spot the plane in the sky, click the plane on the app, and press 'log'.

I think this would be great feature to add to the app, but presumably you'd have to set up a username etc to log all the info.

Perhaps this could be a new feature to add to the app?? Would anyone else be interested in this?