This app was built as part of a special BBC 4 programme on gravity. It uses your current location to work out how much your personal clock is affected by Albert Einstein's theories of special and general relativity.
The app calculates the difference in the rate at which time flows for you compared to someone standing still at sea level (measuring what is known as International Atomic Time) - the app shows how quickly or slowly you are ageing compared to this person.
* Records how much time you have gained as a result of general and special relativity.
* Displays the time gained per day.
The app uses your current location to calculate how your rate of ageing varies. This takes into account both your location and speed. The app records your location when it is open, and in the background to get a more accurate understanding of your own personal clock. We have worked hard to make this background collection of locations have as little impact on the battery life of your device as possible, while also providing you with the option to turn background updates off. Continued use of GPS running in the background can dramatically decrease battery life.