Lantern! app for iPhone and iPad

Lantern is an iPhone application that allows friends and family to check-in with each other to say that they are safe. After you select someone, then they need to check-in at a pre-determined time interval. Only if they fail to check-in, is their last known location revealed.

Examples of use include, making sure your children are safe when they are out with friends, tracking students on field trips, and ensuring loved ones safe on long journeys.

Disclaimer: Lantern uses the GPS component of your iPhone to monitor your location. Lantern only uses the GPS device while you are the target of an active session. Continued use of GPS running in the background can dramatically decrease battery life.