It looks like you're new here. If you want to get involved, click one of these buttons!
Can someone please explain me how to retrieve the device ID which is unique? Is there a built in function for this in Android?
You can use Settings.Secure#ANDROID_ID to retrieve the Android ID as an unique 64-bit hex string.
private String android_id = Secure.getString(getContext().getContentResolver(),Secure.ANDROID_ID);