A new, Wi-Fi connected device called the Heat Meter allows homeowners to track propane, natural gas or oil use in real time and compare their home's efficiency with others in the area. The small unit attaches magnetically to a furnace or boiler and listens to vibrations and when the unit's flame ignites. Since most heating systems burn fuel at a constant rate, as long as the Heat Meter, made by Y Shape Inc., can detect how long the flame is burning, it will be able to accurately predict energy costs. Homeowners will need to input their home's square footage.