the applications

First-party and third-party apps for mobile devices allow users to locate and reserve vehicles. When reserving a car online, the customers are able to see the car's fuel gauge (gasoline-powered cars) or the battery's state of charge (electric-powered cars), so if the customer wants to go for an extended drive, they can find the right car for that trip. Customers can choose to refuel a vehicle to gain free usage minutes.

source: http://en.wikipedia.org/wiki/Car2Go