A dongle created by Columbia University researchers can turn any smartphone (whether iPhones or Android devices) into an HIV and syphilis tester. Even better, it only takes 15 minutes and a tiny drop of blood to get a result -- the device doesn't even need a battery to work. According to the paper the researchers published in Science Translational Medicine, the dongle performs enzyme-linked immunosorbent assay (ELISA) to detect HIV antibody, treponemal-specific antibody for syphilis, and non-treponemal antibody for active syphilis infection. Labs don't currently offer the three tests needed to detect those in a single format. ELISA machines, by the way, cost around $18,000, but each of these dongles only cost around $34 to manufacture.