Its not a purchase as such, it a free app which I have used all this year. I downloaded Zello, a walkie-talkie app and I think its potential is really great. I opened it up and it offers the user the opportunity to have your own free channel. I called mine 'UK BACKPACKING' and when I've had the chance I've asked hikers to download it as well.
The time it worked best for me was during my last hike in the Pyrenees. I was going towards the Bay of Biscay and I met a bloke, Martin (from North London) who was walking to St Jean Pied du Por. He had never hiked before and his rucksac was SO, SO heavy! I helped him sort out what he needed and what he could send back home. We then had a few drinks and a meal together.
I also downloaded Zello onto his phone and about a week later we had a two way conversation about his hike and where he had made it too. He was in St Jean and was making plans to carry on through Spain on the Camino Francais trail. I haven't heard from him since then but am hoping to find out if he made it to the end? I also used it to talk to my niece, nephews and a couple of friends whilst en route as well, great fun!
The beauty of this app is that people, even groups of people can talk at the same time and no one needs to know anyones telephone number. In my case the link between us is just 'UK BACKPACKING, that's all anyone needs to know.'