In my opinion, this app is truly INTRUSIVE. Clearly, someone else has DUO MOBILED UP MY OWN TELEPHONE NUMBER, & I would rather this app not even exist in the first place. The Google Authenticator is much more appreciated by me OR the option to have a text message sent to your current WORKING DEVICE. My accounts are ALL HACKED RIGHT NOW BECAUSE OF THIS SHI*, & like I said before... this app, in my opinion, is ABUSIVE. I would rather it not exist.