Hi, I am a frequent user of Gas Cubby and I've bought almost all available gas tracking application from App Store and currently I've switched to Gas Cubby permanently. I like it very much, although I see a lot of things that could be improved.
1. Gas Price Per Liter Chart - could be customizable to group by gas brand, tag or octane (currently it's grouped by octane and since octane choice is not customizable yet, it's unusable to me).
2. Total Gas Expenses Chart - I don't see any point in this chart unless there's an option to see average expenses per month/week/day. Sometimes I fill 10 L, sometimes 60 L, sometimes I fill-up several times a day, sometimes once a week... Now I see a useless earthquake diagram

A bezier curve that shows average expenses per month/week/day (customizable) would make a real difference. Any point on curve would show how much money/fuel would I spend per month/week/day if current MPG value would be fixed.
3. Partial fill-up could use a slightly different icon in the list.
4. Typing for Liters/Cost-per-liter/Total-cost should start with whole number unless I tap "." to enter fractions (a predictable behavior for any calculator by the way).
5. Digital keyboard could mimic calculator style and not a phone style (zero — left-aligned and bottom-right button could be enter/done, at least for odometer). I know, it's already done in beta, but my point is about enter/done button.
6. Gas price could be pre-filled based on gas brand/tags/octane/previous_entry
7. I like grouping Liters, Cost/Liter and Total Cost during data entry. What I would like to see is adding odometer readings and full/partial selector to this group. That could double data entry speed for me.
8. The ability to swipe left/right in charts and zoom in and out in timeline.
I will really appreciate to have my ideas commented by developer.

Thank you!