It would be great if a web interface would be available, where I can monitor and share my mileage with others! ;)

I don't know if it's possibile, but also a sync with spritmonitor.de would be great!

Syncing between mobile and desktop application would be nice and in demand.

Big screen at home would be far more convenient to analyze the data entered on the road onto the tiny mobile phone.

1. No decimal fraction available for trip and odo meter - this cause application unusable for me.
2. No change odo <-> trip meter during edition, I by mistake entered odo instead of trip and cannot change it. Important usability issue.
   

I think it will be good to be able to change the app language with the settings. I prefer using my country language, but my phone is set on English (because of other reasons).

The app creates duplicate Android/Fuelio folders when it backs itself up. 

Do you know if I export data from anoher app (aCar), will I be able to import it into fuelio?

When I add a service cost at 50000km with reminder at 60000km I expect the progress bar to show 0% at 50000km, 50% at 55000km, and 100% at 60000km. Unfortunalety the app shows it wrong: it starts at about 80% (looks like it ignores the starting odometer, and always counting from 0km).