+ 1 for the Revolut card - but be prepared to see just how much you spend in coffee shops! It’s easy to apply for and as well as showing you what you’re spending money on, you can split bills with other Revolut users.
I use an App called Money Lover. I have to manually enter all my transactions. Well, I put in my monthly standing orders/direct debit and then input my other spending. Having to admit to all my spending at the end of the day can help keep me in track! I use my Revolut card a lot so generally I can just look back on that and see how much I've spent.