The team have borrowed a trick from computer science to achieve speedier loading. Called predictive caching, it involves guessing which software routines are most likely to be needed for the next stage of a computerised process, so that the right app is primed to run when called on, without booting from scratch. The system uses the phone's location and motion sensors to learn when the user typically runs the app.

Imagine that, as you walk to a railway station each day, you normally get to a certain street corner and open a train times app to see if the trains are running to schedule. The software checks the time you usually do this, senses that you are walking and preloads the app, with the current train info retrieved by the time you arrive at the corner on which you normally request it.

In tests, the software cut 6 seconds from the average 20-second boot-up time for apps on Windows phones - although it gobbled 2% of the battery per day while doing so.