Hidden city tool?
 

Hello all, I guess my title says it all.

I'm looking for a hidden city tool which ads a further leg to my original flight, making it cheaper.

I know it might sound strange, but chances are very high that I will fly that last leg and even book a Hotel there (as long as it is a place I've never been before or I like). I see this as a free addon!

:)

Thanks for advices!