The Gas Mileage Android app was developed because I couldn't find any existing (free) apps that would allow me to import the data I had already collected for my car. So, I created my own. This app keeps its data in a CSV format on your SD Card. This means that you can copy that file off your phone to use for some other purpose. The app itself will also allow you to e-mail the file -- just to make it easier.
The data is displayed on the screen sorted by year. Pressing on the year will expand the months, and a press on a month will expand to the days in that month for which you have entered data. A Long press on the year, month or day will pop up a dialog with extra information.
You can also calculate the amount of money you would have or have saved if you were driving a vehicle with a different MPG than the one you have now. Useful in justifying a purchase or to see if it would really be worthwhile to get different car.
The code is open source and you can download it from the downloads menu of the website: http://www.vinginmedina.com.
If you have any problems with the app, please e-mail support@vinginmedina.com.