I miss monzo so much :(
I moved out of the UK and sadly never found a real alternative.
I had a simple workflow that made me happy:
I had two budgets, one for fixed spenses such as rent and phone, another for everything else (food, taxi, entertainment, whatever). I'd divide my "everything else" budget by 30 and tell monzo to move everyday that amount into the credit card account.
So basically... A daily budget. It was something like 20-30 pounds per day. I wanted something more expensive than usual? I'd "save" for a few days.
It's not the most efficient budgeting, but it was so much fun.