sorry for the delayed response, here is the link to the one I got:
Winnes Small Gps Tracker for Kids Elderly Wallet GSM GPS Real Time Outdoor Anti Lost GPS Tracker Locator With App for IOS and Android: Amazon.co.uk: Electronics & Photo
www.amazon.co.uk
I just attached it with a velcro pad, its up to you where it goes, either on a leg or on top of the drone itself.
All you need once you have bought this GPS thing in a PAYG sim which I also got from Amazon, note not all SIMS will work as they need to be compatible with 2G network. The one I had from Three did not work, below is the link:
Shop O2 SIM Card UK & EUROPE (ROAM FREE) PAYG £10 Bundle -7GB DATA + Unltd Texts & Mins + International Calling Option - (Love2surf RETAIL PACK). Free delivery and returns on eligible orders.
www.amazon.co.uk
It will work no matter how far away your drone flies, so lets say you loose all control and it eventually lands 10 miles away when it gets to the emergency battery level you can still find it. It's basically like phoning someone on their mobile.
All you have to do is call the number that is for your SIM, hang up when you hear it ring, and then within 30-60 seconds you get a text from it which contains a google maps link.
When I had my flyaway I even used the google maps link on my iphone as the sat nav destination!!
As I say worth its weight in gold. If anyone has come across anything that is even smaller than this I'd love to hear about it!