Google can already point to example apps, both of which involve driving: QuickBooks Self-Employed uses the kit to accurately track mileage, while Life360 can provide a timeline of drives.

As you might guess from this, the possibilities are relatively narrow right now. Google plans to add more activities to the Transition framework over time, though, including an ability to account for trains and other vehicles. It'll take a while before developers latch on to the feature, but you could eventually see many apps that account for what you're doing without asking you to lift a finger.