Prader Willi really interests me. I understand that people with PW have lower IQs than the general population. That's sometimes the case with people with Autism. Mobile apps or visual aids seem to be helpful in creating a routine and giving them something to look at as a reminder, like: wake up, get dressed (with each step, like putting socks on, and then shoes), etc... I've seen several documentaries abou  3c6f  t PW and I've never seen any binder, poster or mobile app with something food related being used. It's always some person like a mother or worker/caregiver telling the person 10001 times that they can't eat until lunch or whatever. Some people with PW seem to have the ability to have more independence. Maybe they could use an app where they can "spend" a certain number of calories with each meal. They can choose what to eat within that number of calories, to give them more independence... Even people with a lower level of comprehension can be given a simple choice, similar to how you would ask a kid "would you like to eat peas or carrots?"