Hi. I have read previous posts on the general topic of protecting an App using the device Id. As a matter of fact I would like to "bind" my App to a device only. My App is not sold on GooglePlay and my needs are very basic. I don't expect any serious hacker to be interested in my work. It is just a basic "precaution". I plan to put a list of allowed Android_IDs on my server and check through Internet if the calling device is among them. It is not clear to me whether I can use Phone.GetSettings("Android_id") or not. In fact I saw posts where it was expected that future Androids will not give it (or maybe it was the MacAddress to be the object of the discussion). I did tests on Android 7.0 and things go well, but I don't know what happens in other cases. Finally the question is : may I use the Android_ID for my needs or not? . Thanks for any hint.