I also use an anchor alarm app. I've tried a few different ones and I keep going back to the first one I used. It has the remote feature so I use my iPad and leave that on the boat with the remote transmision to my phone. It is called Anchor! and I think it is by Pomacanthus??? Make sure your device isn't on silent because then you can't hear the alarm when it goes off. Also, make sure to that the device that the app is on is plugged in as it does drain the battery overnight. You haven't really had a true sailing experience if you haven't had the anchor alarm siren jolt you out of a deep sleep in the middle of the night...only to find that it is a false alarm! LOL!