It is useful
It is important to know where the money goes each month. A portable housekeeping book will help you with that.
If you use Finance Mastery to keep track of your finance you will be able to see statistics about where your money goes.
Do you want to know, for example in which
Categories (e.g. "food", "clothing"), you spend your money? Finance Mastery does all this with just a few clicks.
In addition, you can easily see the price areas, where you spent most of your money to. Do you leave your money in articles priced 10 to 25$? Or does your money go to low prices goods?
Also Finance Mastery will keep track of your credit card limits.