In reply to Rob Exile Ward:
Worth having a look at Starling. Similar to Monzo in that it's app based and can be set up in minutes.
It's basically a bank account, you can, if you want transfer all your banking to it outright, or use it as a second account.
Overseas - zero commission and MasterCard rates on cash withdrawals and payments. The advantage versus Monzo is no limit of £200 per month for cash withdrawals.