We did use Go Henry, but they charge a monthly fee to have the account and then when a transaction between two Go Henry accounts went wrong and our daughter was missing £30 from her account it took me ages to get the money back from them, weeks of phone calls etc, so I wouldn't recommend them and we closed our account. However, I see Lloyds have a new 11-15 yr old account and others for up to 19 yr olds, which look good. Our daughter is now with HSBC but I can't see her spending on a shared app, so I may well switch to this one.
https://www.lloydsbank.com/current-acco ... start.html