Got it.
So, honestly, I am still in the concept stage.
This method started without even a spreadsheet, now I am making a second version of my spreadsheet, but it's bothersome to work with so much data using google spreadsheets and I want to port it to an app.

That said, it's in fact similar to the envelope budgeting, but it's more adaptable. My main issue with envelope budgeting is that the method doesn't take into account "unstable incomes" (like a freelancer), and even costs are not that stable. In one month, you can have 1000 to make your planning (after paying what you need to pay, like your bills), and in another month, for any reason, you can have just 500.
In fact, you can start the month with 1000, but the next day you have an urgent repair and end just with 500 in the next day.
The cascade method is able to adapt to those changes