Previously if you looked at a flamechart of an app launch, you'd see our App Start transaction and spans, but profile data would be pretty lacking, only being able to start gathering execution data after calling Sentry.startWithOptions:

Now, you can get more data on what runs before main(), like if your code or dependencies have long-running routines in places like +[NSObject load]:

Check out the Android and Cocoa docs for more info.