I’m developing a mobile app for both Android (Kotlin) and iOS (Swift), and I need to identify where the app installation came from.

Use case

On the website, we show a popup like:

> “Install the app and get a coupon”

User flow:

1. User visits website

2. User clicks popup/banner

3. User installs the mobile app from App Store / Google Play

4. User opens app and logs in

5. App should know the install came from the web popup campaign

6. Backend sends coupon to that user

What I want to achieve

I want to track:

• install source

• campaign ID

• deferred deep link information

• attribution after first install

• connect web campaign → app install → user login

Questions

Android (Kotlin)

• Is there an official way to detect install referrer?

• Should I use:

  • Google Play Install Referrer API?

  • Firebase Dynamic Links?

  • AppsFlyer / Adjust / Branch?

• How can I pass campaign parameters safely?

• Example:

  myapp://coupon?campaign=web_popup_001
  
  

iOS (Swift)

• Since App Store does not support install referrer like Android, what is the recommended approach?

• Is Universal Link + deferred deep linking the correct solution?

• Which service is commonly used in production?

Additional requirements

• Need to work after fresh install

• User may install app first and login later

• Need backend to identify campaign and reward coupon

• Prefer official or stable solution

What I already researched

• Android Install Referrer API

• Firebase Dynamic Links (seems deprecated?)

• Branch.io

• AppsFlyer

• Adjust

But I’m not sure which approach is recommended in 2026 for cross-platform apps.

I would appreciate:

• architecture suggestions

• recommended SDK/services

• sample implementation flow

• best practices for Kotlin + Swift apps

Thanks!