Android throws broadcast on installing app . You could receive it in receiver and launch from there.
<receiver
android:name="com.your.receiver"
android:enabled="true"
android:exported="true" >
<intent-filter>
<action android:name="android.intent.action.PACKAGE_ADDED" />
<action android:name="android.intent.action.PACKAGE_REMOVED" />
<data android:scheme="package"/>
</intent-filter>
</receiver>
<uses-permission android:name="android.permission.BROADCAST_PACKAGE_REMOVED" />
In receiver add this :
@Override
public void onReceive(Context context, Intent intent) {
//start activity
Intent i = new Intent();
i.setClassName("com.pkg", "com.pkg.yourStartActivity");
i.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
context.startActivity(i);
}