Not sure what a "rolling FP" is. If you do not have a smartphone, but you have a computer with internet connectivity, (which you must since you posted here), you set up an account on My Disney Experience and link your admission ticket to that account. Once you do that, you can use that computer to book your first 3 FP for each day well in advance. No smartphone needed. Once you are in the park and have used up your 3 FPs, you take your admission ticket, (or Magic Band if using one) to a kiosk and tap your ticket (or band) to the machine and the machine will recognize you. Once recognized, you use the machine (like an ATM) to book your 4th FP. And so on with your 5th-20th. No smartphone needed.