While waiting for the water to warm up or shaving, you don't need the full power of your shower head. EvaDrop is a smart sensor that attaches to your shower and adjusts the flow based on your needs and saves water in the process.
The sensor can cut water use by as much as half, and even lets users set goals for taking shorter showers.
EvaDrop has gotten a boost from water-saving fund Shock the Drought, and will donate 600 units to California residents. The first orders ship in December.