Your comments

Do you have any errors? I didn't change main function connected to GPS. I've removed only some nested fragments and now it should be working in background.

Remember, you need internet connection to get your city name. Do you have internet connection while searching for location?

Try to test it again on open field. Go outside, go to "Add" page and tap on "Save GPS location". Give your phone some time. 

Any errors?

Units were moved to Viehicle's list. If you want to set units now go to Vehicle's list.

If you have old CSV format - go to Settings and there is setting for old backup CSV format. 

Yes. Sorry but Fuelio doesn't have at the moment miising fill-ups feature.

The best way to continue is to create new vehicle. You won't loose stats on the old one.

It's on my todo list and I want to add such a feature. At the moment I need to move all units settings to vehicles and this is something I'm working on.

Yes. You can install it on any device with the same google account. 

About this error. I think you don't have proper version fo "Google Apps". This is common problem for example in CyanogenMod. You need to install it manually to get all google apps work properly. 

Looks like S3 clone. It's hard to say what the put in there. Is is clean Android or some kind of fork.

It's not my fault. Your device could be blacklisted in Google or you don't have Google Apps installed there.

Fuelio is using official Google API. You need device with Google Play Services. 

Maybe you can change ROM on this phone? 

Yes. I'm using textAllCaps. But this should work. So there is probably a bug in Android OS with your language. But maybe if you'll set the phrase (this one below) it will be ok?

The charts are a little bit different than log. There are short version of dates. I'll think about creating option for that.

What do you mean "tones"? 

Maybe this is connected to Greek translation. 

You can check Greek translation and maybe you can fix Greek phrases there?

No. You don't need PRO to calculate such a things. PRO version is additional module for Fuelio with Costs.

To see fuel consumption you need to input at least 2-3 FULL fill-ups. If you have only partial fill-ups I can't calculate them. You need to enter more full fill-ups. 

Try to update Fuelio to 2.9.4 (released today). This bug was fixed :)

The app you have tried probably also is doing it wrong.It was fixed some time ago. This is a little bit tricky. Many people think.

The right data you need to use to calculate real fuel consumption (for your example is):

1837 - this is good!

142L - this is bad. 

114L - is good for your example

You can't use: 1837 and 142.03l to calculate avg fuel consumption.

1837 and 142 - 28(!) which is 114. This is the real fuel you've used. You can't use fuel from the first fill-up for that.