One quick thing you’ll want to enable while developing is the DebugView in Google Analytics. It is a live-ish stream of events from the device, and very useful to begin to understand how your application is understood by GA.

Head over to the docs for a thorough understanding, or just follow along here.
To enable it, you’ll need to pass this argument in XCode:
-FIRDebugEnabled
And that will persist until you explicity ask it not do via:
-FIRDebugDisabled
So let’s do it now.
In XCode, head over to Product > Scheme > Edit Scheme (⌘<
)

Then Run > Arguments > Arguments Passed on Launch, and paste the enable/disable command.

That’s it! Now inspect your XCode Debug area and/or the GA DebugView screen.