The idea of an escrow style envelope that could be mapped to a savings account. This would be for similar items that are more like things paid from a mortgage escrow account infrequently where the "minimum balance" required is calculated so one would know how much needs to be contributed to keep the escrow account on track.
For instance, a person with a paid off house still needs an escrow-like savings for their annual home owner's insurance, and semi-annual property taxes (in California due Dec & Apr), perhaps HOA fees, etc.
Another use for this sort of escrow account could be related to vehicles: paying auto insurance semi-annually, license and registration fees annually, smog certification every 2 years, tires every 7 years, other "big ticket" maintenance items, etc.
I have a number of related "education" items I have to renew on a 1, 2, 4, 5, 8, and even a 10 year basis. Right now I track all of these in a spreadsheet and then divide each by the yearly amount, total the yearly amount, and divide it by 26 paychecks. It mostly works, but I'd like to use fewer spreadsheets and have more "reminder" features for these infrequent items.
So this would allow a person to basically have an "escrow" savings account which could have many similar items that are paid out of it. The items should be able to have a name, a link/description/renewal info field, amount due, and next due date, and frequency of payment (every 6 months, 1 year, 10 years, etc.).
My credit union allows me to have an amount of "sub accounts" (4) for savings for no additional cost (Ally Bank calls these Buckets, some credit unions call them Super Savers or Special Savings). These sub accounts could be grouped and used with these escrow envelopes, as examples given above typical uses would be: Home Escrow, Auto Escrow, Education Escrow, and Income Tax Escrow.