• With this free Voltcraft Smart Thermal APP and the Voltcraft WBS-220 you can detect thermal images and temperature from your Android smartphones and tablets • It doesn't need any battery, working by just inserting the USB interface into the smartphones or tablets. • It is compact and portable, can be used to detect thermal images and temperature at anytime, anywhere. • allow you easily spot invisible heat sources • Display the thermal image on the better screen of the smartphones or tablet