Scavenger - An augmented reality scavenger hunt for cash prizes
Treasure Hunt - A scavenger hunt app for kids, powered by machine learning
Geocaching - Geocaching is the premier app for locating geocaches. This app is available for both the Android and iOS platforms, and it makes locating these popular hidden treasures easy and fun.
Wordup - Wordup CLI is an open-source development toolkit for setting up and managing your local WordPress theme or plugin development
Play Munzee - Similiar to Geocaching but requires players scan a QR Codes instead to validate find.
Think with Google - Put Google research and insight behind your thinking.