I am using Google Analytics iOS SDK (version 2 but will upgrade if it solves problem). How can I track what percentage of my app users have pressed a certain button at least once? I set up a lot of event tracking, thinking this would do it, but the reports are in terms of sessions not users. E.g., it will show what percentage of sessions included an event, so a single user may be counted multiple times. I defined a custom dimension variable that is unique for each app install, but I don't see how to use that as aggregation unit.
All I can think of is to define my own "one time events" by keeping my own database on the device and only pass to Google Analytics the first time it occurs. Is there no better way?