The OnTrees app is a personal finance app that allows you to see all of your banking accounts in one place. Not only that but it can aggregate your spending habits and analyse them to show you where you are spending your money.
I always like these sort of apps because they can offer you an easy snapshot of what you are spending your money on. If you can manage to get all of your sources of spending, e.g. current accounts, credit cards etc. on to this app then you will have a true picture of what you actually spend in reality.
Knowing what you spend is difficult to calculate unless you either trawl through your statements, keep an old fashioned budget, or use an app like this.
There are more details about the app here: https://www.ontrees.com/ and I think it is only available via the App Store, i.e. not Android, for now.