SureKey
SureKey is a key cover that will let you know if you left your door unlocked. When you first set it up, lock your door with the SureKey attached to your key. From that point on, it will blink green if you locked the door and red if you left it unlocked.
Crowdfunded projects pose a degree of risk for buyers, so be sure to do your research and fully read the seller's detailed description and production plans before plunking down your hard-earned money.
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