You can send and collect data from your mobile apps to your Google Analytics account which will appear in your Mobile App Sources report by following few steps listed below:
Enable app install tracking in your Google Analytics account
Android users: They don’t have to select anything because app install tracking is enabled by default for Android apps.
iOS Users: Sign in to Google Analytics and select Admin tab -> In the ACCOUNT column select Analytics account and in PROPERTY column select property then click Property Setting -> Then in Compaign Tracking Section click toggle to turn it ON and then save the setting.
Update Google Analytic SDK
Android Users: Refer to Android Developers guide to change a few lines in their manifest file.
iOS Users: To access the iOS identifier for advertising (IDFA) you need to add libAdIdAccess.a to XCode project.
Setup custom Compaigns
It is the feature that add parameters to the URL of your marketplace page where users download your app which tell Google Analytics what marketplace your traffic comes from.
Create and manage ad campaigns
After setup you can start to think about your advertising strategy and content. You can use these add compaigns for selecting your target audience and conveying your messages.
By completing all above steps, your data will appear in Mobile App Sources Report.