We're here to help. Whether you're having issues with Presence or you have a great idea for a new feature. We want to hear about it. Seriously.

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425 Broadway Street
Redwood City, CA 94063

Presence is the award-winning free app that turns old smartphones and tablets into Wi-Fi security cameras and you can download it today.

Presence Security is the addition of easy to install wireless sensors that notify you and your trusted circle when something important happens to fit with today's mobile lifestyle. No monthly fees are required! We want security to be affordable for everyone because we all have homes, loved ones and valuables that we want to protect.

How our Entry Sensors Work


How our Entry Sensors Work

Brian Hinderberger

The Entry sensor comes in 2 parts: the small magnet, and the larger transmitter.

When the magnet is far away from the transmitter, the sensor reports "Open". When the magnet is close to the transmitter, it reports "Closed".

It doesn't matter if you put the magnet on the door and transmitter on a door frame, or the magnet on the door frame and the transmitter on the door. The only thing that matters is that you align the arrows pointing toward each other, and keep the gap between the magnet and transmitter smaller than about 0.5" / 12 mm.

  1. Peel off the sticky backing from the magnet and the transmitter.
  2. Stick the magnet to the door or window frame, stick the transmitter to the door or window (or vice versa).
  3. Inside the Presence app, test to make sure the entry sensor reports "closed" when the door or window is closed, and "open" when the door or window is open. You may need to refresh your list of devices to get a faster update, or tap into the sensor's user interface.

It's possible to install the magnet at an angle (even rotated 90 degrees!), but always test it in the app to make sure it's working as you expect.

The Entry Sensor will automatically alert you when its battery is getting low. It takes a CR2032 Lithium coin cell battery, which should last a few years.