Looks like it's similar to the GoHenry app that launched year's ago and was really good. However they started charging a monthly fee and I'm not sure it was justified.
It's called Starling Kite.
https://www.starlingbank.com/current-account/kite-debit-card-for-kids/
"Starling Kite: digital banking for young people aged 6-15.
It’s like a child bank account, but built seamlessly into your account for better visibility and control. Once it’s set up, transfer money into their Kite Space in seconds and help them learn money skills for life.
Kids get their own version of the app, where they can track their spending, start budgeting, and save for goals. You’ll be able to keep an eye on things from your own app, and set limits if you want to. It’s simple, secure and convenient banking for kids. Plus, Kite customers get a free kids meal at the National Trust!"
Sounds great but no ideas if it actually is.