Worthless. Although the app had worked great for months, following the January 2022 Microsoft Surface Duo (Android OS) update, this app fails to even log in to the Adt server. Dispite my contacting Adt service TWICE no update to this app has been made to correct the problem. Also, TWICE the Adt personnel took my info with a promise that a tech person would follow-up with me, but crickets is all I hear.