Your weekly budget on your home screen. Apple Pay updates it, every time.
You need an iPhone on iOS 17 or later and a card in Apple Wallet.
Copy it, open Scriptable, tap +, paste, rename it Spend Less.
Set your budget, add the widget, connect Apple Pay. Every tap shown, 20 slides.
Scan with your iPhone camera. Scriptable, the copy button and the widget all happen on the phone.