I don't know, I quite like it. The monthly fee is minimal really and it's quite useful in that you can have an app and monitor things/create job lists/savings pots etc. I think it's a good introductory tool into managing money properly and in a format they can see, rather than just a lump of money in a bank. I don't think it's a long term thing for us, maybe just a year, but my daughter has just turned 11 and it's helpful.
You can set how much (and that can be zero) they get topped up every week and you can just transfer into it as and when, it's like a lot of things, if you take half an hour to work out the app and read it all, you won't end up in a pickle. If you know someone who has one then they can give you a referral code that gives you some money and usually a month or two for free so you can investigate without the pressure.