The Toolkit For YNAB, a third party browser extension, has this very "Pacing" feature. While not available on the mobile devices, it's pretty sweet on the main interface. I have no idea why YNAB hasn't added it to the stock app by now (along with a number of other useful features).

Alternatively if you don't wish to venture beyond the stock YNAB, it's pretty easy to gin up an auto-incremented category, say for a week's worth of money at a time with recurring, scheduled transactions. I suppose updating daily is possible, but I'd probably put those transactions in a dedicated account to reduce clutter.

Use two categories: a Grocery and a Grocery Reserve category, for example. On the 1st of the month, transfer the monthly total from Groceries to the Reserve with a net $0 scheduled/recurring split transaction. On the 1st, 7th, 15th, and 22nd of every month, transfer 1/4 of the total from the Reserve to Groceries, again with a net $0 scheduled split transaction. Reports correctly show $0 spent in the reserve category after the month is over.

I love the Toolkit Pacing feature.  And you can turn on and off the categories you want to pace on the fly.  Like, I don't want to pace mortgage because I pay it on the first of the month and don't want to see I'm 30 days behind for the rest of the month, and I can just unflag it.  

I just wish when I tell my husband that we really should lay off grocery shopping for the next 3 days he ignores me.  But that's for another post! :D