Ages ago, my tool tried to do both weekly and monthly but then I had the realization out that almost all of the monthly items were not ones I was having trouble with in the budget. The fixed expenses were (obviously) fixed. And consumption-based utilities would vary month to month, and that was easy enough to track and reconcile every so often.

In other words, the budget would get "broken" more often in the week-to-week habits than the monthly ones... hence, the resulting focus of my tool.