I use an app called spending tracker, it's got a picture of a wallet.
It is a very simple app, but takes a bit of work setting it up but i love it.
So I have a current account set up and then from the current account I allocate pots of money. So groceries, bills, savings, car, holiday, eating out, mortgage, house repairs, petty cash. For example £1,200 into the current account. Then from current put £400 into mortgage, £100 to car, £100 to groceries, £300 to bills, £50 savings, £50 holidays, £100 house repairs, £40 eating out, £60 petty cash.
Then as you spend from each budget, reduce the balance by that amount. Eg£40 petrol comes out of the car budget. If you don't spend anything one month it stays there saved ready for when you do need to spend it.
It's a version of envelope budget and really helps me to keep an eye on what is being spent where.