Google Analytics is a freemium analytics service, that tracks and reports traffic. You can use this great service to track user behavior, also of concern on WordPress mobile app to have good tactics.
Get Google Analytics tracking ID
First, login to Google Analytics here, if you no used Analytics before, click [ Sign Up ]
Otherwise, you need to create a new property.
Select property for Website, then fill in information and click [Get Tracking ID]
As a result you will get a Tracking ID, please remember it to configure it in the next step.
Now click [ ADMIN ] go to Admin page
In View, click [ Create new view ]
Select [ Mobile app ], input infomation and click [ Create View ]
Final, use the Tracking ID you got above fill to Stionic menu General tab on WordPress Dashboard.