Engineers at Cornell University have designed the smartphone app that allows you to monitor your own blood cholesterol levels.
An attachment fits over a smartphone camera's flash.
Users put a drop of blood on a color-changing test strip, then into the attachment.
The phone's camera can see the color of the test strip.
Researchers say the app will eliminate the need for costly equipment and lab testing.
Cornell is also working on an app that can test Vitamin D levels.