When you own a Rocket keeping a note on fuel consumption isn't really necessary. However, as an exercise I find it quite good to keep a record so I can see what is happening when I am out. A bit of fun.
Oddly, the app that worked on the iPhone doesn't work on the Android, so after ages I found Fuelly. It shares with other users and I need to see if there are other Rockets on there. So over the coming months I'll be able to track the consumption on trips.