Your spending has value. You're losing most of it.

Every card pays more on some things than others, and keeping track of which is which is the part nobody does. SwipeFund reads what you actually spend, works out which card pays most on each purchase, and tells you before you pay instead of after.

When a purchase goes on the wrong card, it says so, and what that cost. It never asks you to spend more. It only asks you to take back what's yours.