A growing trend in mobile phone applications is more location-based apps that know where you and/or your friends or co-workers are and utilize that data in some way. Augmented reality apps use GPS coordinates to provide context specific information. Products such as Brightkite enable users to "check in" at various locations in the real world and see who else is there, has been there, and who is nearby. Additionally, a number of learning and team building activities have been built utilizing location information.