Hey there! I’ve dealt with this exact scenario while building rider/driver apps like Uber and Careem—let’s fix this issue for you right away.

The root cause here is super straightforward: Android uses the application ID (aka package name) as the unique identifier for every app. When you copied your original project, you kept the same application ID for both apps, so the system sees them as the same app and won’t let you install both at once. Here’s how to fix it:

1. Update the Application ID (Critical Step) #

This is the core fix—you need to set a unique application ID for each app in their module-level build.gradle files:

• Open the first app’s build.gradle (Module: app) file, look for the defaultConfig block. You’ll see a line like applicationId "com.yourcompany.taxiapp".
• Now open the second app’s identical file, and change the applicationId to something distinct. For example, if the first is for riders, use com.yourcompany.taxiapp.rider; for drivers, go with com.yourcompany.taxiapp.driver.

Example of the updated defaultConfig block:

defaultConfig {
    applicationId "com.yourcompany.taxiapp.driver" // Unique ID for driver app
    minSdkVersion 21
    targetSdkVersion 33
    versionCode 1
    versionName "1.0"
}

2. Check for Other Potential Conflicts #

While the application ID is the main culprit, there are a few other places you might need to tweak to avoid hidden issues:

• Custom Permissions/Components: If your apps use custom permissions, Content Providers, or Broadcast Receivers, make sure their android:name or android:authorities values don’t reuse the old package name. For example, a Content Provider’s authority should now use your new application ID as a prefix.
• Project Folder Names: This isn’t mandatory, but renaming your project folders to match the app purpose (like RiderApp and DriverApp) will help you avoid confusion down the line.

3. Rebuild and Test #

After making these changes, click "Sync Project with Gradle Files" in your IDE to apply the updates. Then build each app separately and install them on the same device—they should now coexist without any issues.

Pro tip: Keep your application IDs consistent and descriptive. It’ll make managing app updates, Firebase integrations, and other third-party services way easier later on.

内容的提问来源于stack exchange，提问作者Waqas Ahmed