Stray Boots is an App developed in America. You can play a social game, a scavenger hunt, visiting a city alone or with a group of people. First you choose the tour then Stray Boots gives you challenges (asking you to find things, solve riddles, take crazy photos, and answer trivia). Complete the challenges to earn points, play against an other team of friends. After each challenge, you’ll get fun facts about the area. So you’re not just exploring the city, but learning about it as you go.
The App is just available in America and UK.
A Video explains how it works.