Yes. You can use Me2Me transfers in the Marygold app to transfer your money between your Marygold Money Pools / Piggy banks, as well as between external bank accounts. If you transfer funds from any of your non-Marygold accounts then you will need to authorise the transfer instruction in the relevant bank app (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 utilising 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 directly with your bank provider app.