Ingress

Ingress transforms the real world into the landscape for a global game of mystery, and competition. Basically, you can use post offices, sculptures, or libraries to create "portals" on your smartphone and compete in a portal battle with friends! The app was created by Niantic Labs which also created a free Android app called "Field Trip." On November 8th, 2012 the app was created. Ingress is a free app that only works on the Android Platform (Google Play Store). Recently it has been ported to work for iOS devices (Jailbroken or non-jailbroken). Click here to see more info and how to get the iOS port. Since the app is now in closed-beta, you cannot just go to the Play Store and download it. Instead, you have to go to ingress.com and request an invite. Another way to get the app is to ask someone with Ingress to request you. Note: You do need a Google Account and you need to give Ingress your email to be requested. If  Niantic Labs except your request, then you are in the world of ingress!

VERY Basic Ingress Idea (The game is very complex and will take hours to explain): Game play consist of making "portals" at real life bases like art museums, etc. and linking them together to create virtual triangles. For a more in-depth understanding and tutorial of the game, click --> "How to Play Ingress" (video by Tinkernut).  "Our world is at steak, and you must pick a side." Check it out on ingress.com