If you know someone with a compulsive behavior such as nail-biting or thumb-sucking, you may find yourself constantly telling them, "Hey, you're doing it again." The problem is, you can't be watching/stopping them all the time. That's why HabitAware's Liv was created. It's a bracelet that recognizes its wearer's problem behaviors, and vibrates to let them know that they are in fact doing it again.

The first Liv prototype was developed by husband-and-wife team Sameer Kumar and Aneela Idnani Kumar, in order to treat Aneela's compulsive pulling of her eyebrow hairs and eyelashes. It reportedly made a huge difference, allowing her to now have full lashes and brows for the first time in over 20 years.

Here's how it works …

Users start by pairing Liv with an iOS or Android device running an accompanying app, then purposely performing the targeted behavior using their dominant hand, which is wearing the bracelet. Sensors in the device will detect the exact movements and hand-positioning that are involved, with that data being stored onboard.

Subsequently, even when it's used without the mobile device present, Liv will recognize when that same action is taking place, and respond by vibrating. The vibration isn't intended to be an actual deterrent, but is instead simply meant to draw the user's attention to what they're subconsciously doing. They can then make a point of stopping, and perhaps substituting a more positive activity – the app provides suggestions.

Up to eight different behaviors can be programmed into the bracelet at once, with old ones being deleted and new ones added as needed. It's apparently pretty good about not being set off accidentally by actions that are similar to those associated with problem behaviors, although it can be temporarily disabled if it's raising too many false alarms during a specific activity. One two-hour charge of its battery should be good for a full day's use.

Additionally, utilizing the app's tracking feature, users can see if a behavior regularly occurs at a certain time of day. If it does, that may provide clues as to the cause, plus it lets users make a point of watching for themselves doing that thing when that time rolls around.

Liv is currently available for preorder, with prices starting at US$99. Deliveries are expected to begin late this year.

There's more information in the video below.