Easy arming and disarming Alarm notifications Remind Me alerts Nest Detect motion sensor Nest app Tough on bad guys. Easy on you. The Nest Secure alarm system is easy to live with every day. Just tap Nest Tag on Nest Guard to arm and disarm the alarm no passcode needed. Nest Detect sensors look out for doors, windows and rooms. And with the Nest app, you’ll always know what’s happening at home.