Specifically and precisely how did you decide what data you are going to collect and keep on your users with the app? Of that, how much of it is only accessible

Specifically and precisely how did you decide what data you are going to collect and keep on your users with the app? Of that, how much of it is only accessible with an app rather than providing the same thing through a web-browser? edit: I think this is a very reasonable question to ask. I'm sorry it's making some uncomfortable but that discomfort really doesn't change the economic realities of competitive space in the industry.