Here is how it works:
1. Enter the odometer readings along with the quantity you filled. Make sure that you enter full tank.
2. You go for a ride as long as you want.
3. Do another full tank filling.
4. Enter the details again. Mileage is calculated for you.
The features of the app include:
1. Listings of all entries which will be helpful to know past mileages and the spending on fuel.
2. Graph to show the mileage trend of your vehicle.
Currently the app supports only one vehicle.