It would be cool if you could temporarily change the settings in the app so that it displays your balance and spending as equivalent working hours (based on your take-home salary after tax).
I imagine it going something like this:
User inputs some basic info about their salary into the app - in a similar way to a generic online ‘take-home’ salary calculator.
The app works out the user’s hourly wage minus tax and any other deductions (such as student loan repayments, salary sacrifice, pension plan etc.)
At the tap of a button, say in the top right of the app, the user can toggle between normal currency display and an ‘hourly wage’ equivalent.
The app could also house a quick access converter for checking the ‘hourly’ cost of items on the fly.
Friend: "How come you didn’t buy that obscure kitchenware like you planned?"
Monzo User: “I decided it wasn’t worth 15.82 hours of my time”