Time based iOS Auto Start

Question

I am trying to build an iOS app that aids in Ecological Momentary Assessment of Patients. Basically it is a simple survey app that the patients need to take thrice a day.

I am new to iOS development and thus I cannot take some design decisions, I would really appreciate if some of you could look at these design decisions and let me know if it is possible in an iOS app.

1. I want the patients to take these surveys thrice a day after their Breakfast, Lunch and Dinner. So I want my app to auto-start or at least pop-up a remainder for the user to start the survey app and fill the questionnaire. Is this possible?
2. I want to assign a unique ID to each copy of the app, which the app should use to send the data to the central database which resides on the server. I don't want to bother the patients by giving a login form every time they start this app, or even the first time they start the app. So is this possible?

Answer 1

1. Can't auto start app, but you can use local notification to make the patient run your app
2. If you don't need identify each patient, UUID is the unique ID for each device.

Answer 2

That's not possible to start the app automatically on iOS, but you can show reminder in status bar. Use local notifications for this.

Regarding to unique ID, you can generate a random ID on the first launch of the app or just use device's UDID.