Tankbook, the fuel log that shows its arithmetic

Field notes

Entries can begin with a receipt photograph or a manual form containing date, odometer, quantity, and total. The documented checks compare quantity × unit price with the total and flag the field needing correction rather than silently guessing. The log combines petrol, diesel, hybrid, and EV records, preserves foreign-currency values at the historical exchange rate, and offers CSV or JSON export. Pump-display capture, legacy-data import, and CarPlay are described as future or in-progress work.