Yes. You can use me2me in the Marygold app to transfer your money between your Marygold money pools / accounts, and/or external bank accounts. If you pay moving money from any of your non-Marygold accounts then you will need to authorise the transfer instruction in your bank app, but this is a smooth, quick and safe process that utilises Open Banking.
Note, if you would like to utilise the Marygold app to help you better manage your non-Marygold account balances, you first need to link these accounts to the Marygold app via the 'add external account' action. Once complete then you will be able to view these balance from within the Marygold app, as well as utilise me2me transfers using these accounts.
There is no need to add these external accounts if you don't wish, and you can also revoke any permissions granted anytime either within the Marygold app or your directly with your bank provider app.