tl;dr: The Greenlight card and app has been a great solution for auto-managing my kids’ allowance and spending. $5/month for up to 5 kids.
The Solution Greenlight offers accounts for kids that are associated with a debit card and an app. The app allows parents to set up automatic transfers to kids’ accounts, and allows kids to see and manage their own money in different buckets. They also have a bunch of other useful features.