During a paternity leave, I found myself getting into bad late-night snacking habits, so I built Curb. You stick it up in your fridge and set what hours of the day you want to prohibit snacking.
If you open the fridge during a time of day you're not supposed to be snacking, Curb will sense the fridge light and play a gentle melody to remind you of the goal you set for yourself (it's not supposed to be annoying or shaming).
Curb worked and even helped me to stop snacking as often. I used an off-the-shelf enclosure to reduce manufacturing requirements, but bringing it to market still ended up being more than I could handle by myself while also working full-time (and having a new baby).
Breadboarding the prototype
Curb PCB
ICY / HOT
Final Product