Hm. I'm afraid I don't see the point. So I tack in my income, my recurring expenses, and then it tells me my disposable income per month (a static figure)? Wh

Hm. I'm afraid I don't see the point. So I tack in my income, my recurring expenses, and then it tells me my disposable income per month (a static figure)? What is the advantage over just tapping those figures into a calculator or an excel sheet (which is probably easier to update later)?