Here is a smart gadget that lets you control your water heater from your smartphone. The Aquanta WiFi Water Heater Controller shows you how much hot water is available. You will also be able to remotely turn on/off your water heater and put it on a schedule. This controller plays well with IFTTT.
The Aquanta Smart Water Heater Controller lets you keep an eye on your consumption data. It works with natural gas & electric storage-style water heaters.[where to get it]