The app literally sends you a push notification when your LL is ready to be used, when your mobile order is ready, when your ADR approaches, when your LL becomes a MEP (and explains what that is), if I remember correctly it also tells you when you can book another. You don't -have- to know or remember anything. At the most you need to remember to book another right after using it and unless you have MB+ (more fun tech!) then your phone is already open on the app on your hand.
Honestly, it's like folks Pavlov themselves into thinking its the hardest most time consuming thing to do.
I'll be the first to admit the app has lots of issues (at least the DLR one, I haven't used the WDW one in a while). It uses so much bandwidth, it can heat up phones, its slow, its clunky, its homepage is a mess of useless ads and clutter, its probably up there in my top 3 less user friendly apps that I use. But
genie+ functionality and mobile ordering are probably the 2 things it does well.