I guess if I build an android app (no problem with that) that would directly be able to communicate to quadcopter controller (somehow)
Yes. You could use the GSM shield.
It depends on what sort of communication you want to do about the practicality.
SMS can take a long time to be processed by your network provider. I don't even think they are guaranteed ever to arrive.
They would not be a useful form or real time control
You could open a network port on the GSM shield and communicate with it directly from your phone, eg via its IP address
If signal to master controller (my phone) is lost it returns home.
This seems to conflict with the other statements you made
BT and Wifi is not an option since it's short distance.
You could possibly use BT to determine whether the quadcopter is "in range", and the same applies to Wifi
But if it would need to return to you if either of these signals is lost, you may as well use them to send messages to the quadcopter in the first place.
Also. As a general note.
Although doing a quadcopter project is cool etc, I suspect that it would take more time to complete that you'll actually have.
People doing web sites etc are far more realistic about what is achievable.
My final year project was much more modest, an automatic medication dispensing system for people with memory loss, which would keep time, have speech synthesis and dispense the correct tablets.
I thought it would be easy, but I ended up spending evenings and weekend's trying to get it working, and in the end didn't totally complete it.
Yes. I still passed with Distinction.. ;-)