If you take any boiler like electric or gas, they are usually equipped with simple thermostat that controls heating element by measuring water temperature. This is OK in one hand but not so good when room temperature is high enough and you would like boiler to be off even if water temperature is lower than threshold. In order to achieve this functionality you need another thermostat that would measure room temperature and power boiler in desired threshold.
Ktulu built user friendly thermostat that can be attached to any boiler. It measures room temperature using DS1820 1-wire temperature sensor. Boiler is switched using mechanical relay. Other great feature is graphical color LCD (from Siemens M55 phone) where temperature is displayed in numerical and graphical form. Also it helps in changing settings. Thermostat also is equipped with LDR which enables to set night and day modes.