I am enjoying reading this thread as more info. unfolds! This may have already been answered, but how do you split FPs up among your party using the app, and then book subsequent FPs for other party members if your party is not staying together the entire day?
We are going in December with my husband's senior parents, and while one of them does have a smartphone, my hubby and I typically handle the technology aspect of things and make dining reservations/fastpass reservations on the app for all of us. (we have experience with the WDW FP+ system;
Disneyland MP system is all new to us, obviously!) We do like to split up from his parents from time to time on our trips, so I am wondering if I (the primary account/app holder) will have to book their FPs separately from mine and my husband's on the app if we are planning to split up in the parks or just want to do different things at the same time. Then, after they have used their first fastpass, would I (the app holder) have to stay in contact with them to book the next one for them, even though we are not physically together in the parks?
I think we could teach my mother-in-law to use the app, but since all 4 of us will be sticking together for the majority of our trip, it just seems like it would be easier for me to book everyone's FPs at the same time to make sure we all get the same return times. Following that, if we did download the app for my MIL, is there a way to have our 2 accounts linked on the app, with me being able to book FP for all 4 of us, and then if we wanted to split up, with my mother-in-law being able to book FPs on her phone for the 2 of them, and me on my phone for my hubby and me? (Did that make any sense?!)

Basically, I want to be able to book FPs for all 4 of us in the party on my phone while we are together, and then when we split up, it would be ideal for my MIL to be able to book FPs for herself and her husband on her phone since we won't physically be with them the entire day. Is this even possible?
SO MANY QUESTIONS! lol From what I can tell so far the Maxpass system seems to be great for technology lovers, but not so great for those who are older and not-so-tech-savvy.