Ethercache

Ethercache is the world's first digital scavenger hunt, a mobile app that allows you to store hidden messages around the planet, a modern twist on geocaching.
Just give it a try! We think you'll love it.
How to use Ethercache:
1) Go to the place you wish to hide your message.
2) Open Ethercache on your iOS device.
3) Touch the "+" button and wait for the purple pin to drop.
4) Give your new ethercache a name, and a message by touching the info button.
5) Nudge your ethercache a little - but not too far!
6) "Embed" your ethercache.
7) Your ethercache is now available at that location for anyone to find.
8) Have fun!

FAQ:
Q: Just what is Ethercache good for?
A: Ethercache is fun! You can use it for a scavenger hunt, to supplement a geocaching trip, or just to have fun with your friends and family.

Q: Who uses this thing???
A: People all around the world! In the country and in the city, there are user-generated ethercaches in dozens of countries across 6 continents (we're still waiting for someone to leave an ethercache at the south pole!).

Q: Will Ethercache steal all my personal data?
A: No! What you choose to leave behind will be available to anybody to find, but apart from that, we don't use or store any personally identifiable information. And none of the messages you enter are stored on your device.