there is only one budgeting app worth a damn and it's YNAB. i've been using it for years and it's absolutely perfect for my use case of being a weird-ass freelancer whose money comes from like five different places depending on the month. It's Good (tm)
YNAB was, no joke, literally life-changing for me. It helped me climb out of debt, get a handle on how much I spend on snacks, and start saving for a car when I pass my test