WiTenergy Bluetooth Smart Energy Meter for iOS/Android

Here is a smart energy meter that measures voltage, current, power factor, and wattage and transmits the data to your smartphone via Bluetooth. The WiTenergy Bluetooth Smart Energy Meter is also a programmable timer. You can use it to control, program, and monitor energy usage of your appliances. The device does have a manual on/off button.

The WiTenergy E100S pairs with your smartphone or tablet to help you measure your energy usage. It offers overload protection as well. You can find out more here.