One simple device will break down your energy spending, and help you save money.

For time immemorial your energy bill has been a mysterious beast. Is this month’s bill based on a meter reading, or is it an estimate? What does that mean for last month’s bill, and how much do you need to be afraid of next month’s? The Sense home energy system clears up all of the mystery, by breaking down all of your electricity based spending.

The monitor connects directly to your electricity meter, and collects data from every device plugged in to your circuit. It itemises everything using power, and keeps you updated via an app on your phone.

It’ll tell you when each appliance or device is using the most power, and compare usage to previous years. It’ll let you know if some appliances are using more power than they should be, and need to be fixed or replaced. It’ll warn you lights left on when they should be off, doors left open when they should be closed. It’ll even compare the energy efficiency of your home to that of your neighbours.

Currently, Sense only works with iOS, although an Android app is on the way, and it only works with single-household electricity meters. As they’re in the early stages of rolling out the product, Sense is currently only available for early adopters via their website, which does not ship outside the US. The estimate for shipping is September, so if it’s available more widely from then, you could start saving in time for winter.