Rapid diagnostic tests (RDTs) are making disease screening quicker and simpler. Most RDTs are small strips that react and change color in response to infected blood or fluid samples. While they are efficient, RDTs have several problems. They are read visually, increasing the risk for human error, and the results generally fade in a few hours, so a diagnosis can’t be confirmed later. Researchers at the University of California, Los Angeles have created a cell phone device to address these issues. Their RDT-reader attachment, which clips onto a cell phone, has the ability to read nearly every type of RDT when the strip is inserted into the attachment. With the help of the phone's existing camera and a custom app, the strip is converted into a digital image. The platform rapidly reads the digitized image to determine whether the test is valid and if the results are positive or negative, eliminating the potential for human error. After this step, the RDT-reader transmits the test results to a global server, which processes them, stores them and, using Google Maps, creates maps charting the spread of various diseases -- geographically and over time -- around the world.