This project is about visualizing the electromagnetic world around us that is unknown to our five senses. Bubble Finder is an electronic device used for detecting the presence of mobile phones. For the project I developed two versions of the tracking device. One is a standalone version and the other works as an Arduino shield. The boards have a filter that allow only certain radio frequencies to be detected. In this case 836.5mhz for SKT mobile phones. The boards output a signal to the pc which has software that uses Bayesian analysis in order to automatically determine whether a phone is being used nearby or not. The detection of a phone is sent over the network to the computer running the visualization software.