Shows you these values, which are all related to identifying an android device.
Secure.ANDROID_ID (AKA Android ID)
Has a refresh button (Screen shot outdated) so you can refresh the data and see how values changed / become unavailable. Simply touch an item to copy to clipboard.
Secure.ANDROID_ID is mapped to 'android_id', the hexstring of interest is retrieved by
ContentResolver contentResolver = getApplicationContext().getContentResolver();
I made this app to explore ways to identify a particular android device. Identification guide can be found in link below:
and Stackoverflow question is here with solutions