
Find it here:
http://dronetrack.org/
Using an old cellphone as a tracker, you can track a drone online in real time.
Also play sounds, flash the screen for maximum visibility, and trigger an alarm on the drone from the website.
I've tested this on a prepaid account (R100 total cost, the phone was an old one on my contract, so technically a free phone)
This has already helped me find a stray drone (still noob at FPV) and seems to be helping others too.
I put the mobile in a little box and attach it to the drone. Peace of mind!
The advantage is the tracker is completely independent device, so even if your LIPO burns out it will still work.
Let me know of features you'd like to see!