You can install our site as a web app on your iOS device by utilizing the Add to Home Screen feature in Safari. Please see this thread for more details on this.
Note: This feature may not be available in some browsers.
It's definitely related to LED lights. I was having the same issue when parked at home and when I watched the events I could see the flicker with the LED bulbs installed at the entrance to my home. No Sentry Mode when parked at home.