As much as we all love Monzo, there might be a reason to have other accounts too (mortgage, credit cards and other loans). Perhaps have a plug into all these financials (high street banks I suppose) and get a view of all the transactions. Pulling in live transaction data from your other accounts, loans, credit cards and investments.
The high street banks will never be as good and quick as Monzo and so it does need some single place tracking.
The plugin should let us view all our bank accounts in one place and see how your money is coming in (hopefully) and going out (more likely). We already have categories in Monzo and as it evolves have the categories merged. However, have an identifier to easily id the transaction banks.
Sorry if this has been suggested, a quick search did not show up. I did not search well enough if this has already been suggested.
Some of the example services would be OnTrees Personal Finance, Money Dashboard, MoneyHub.