There is a growing number of easy to perform tests detecting a variety of conditions that can be taken at home or in areas without specific medical assistance. They are based on the analyses of a body fluid, like saliva, blood or urine, performed by a small strip of paper containing a chemical that in the presence of certain molecules changes the color of the strip, usually resulting in different hues or different saturation depending on the percentage of those molecule in the fluid.
The trick is to evaluate the hue, or saturation, correctly, something that a trained eye can easily do but an untrained one can easily get it wrong.
The sensitivity of a normal phone digital camera is much greater than the one of our eyes and it can be easily calibrated to distinguish different hues and saturation levels under different light condition, something that for us takes place in our brain after many many trials and error. It is only through experience derived by learning over a lengthy period of time that our brain acquire the "clinical eye" needed to identify correctly a specific color.
This application, now under testing in a variety of environment, can provide a big help to all of us, and even more to those people who don't have reach to a doctor. The test can be performed at home, basically in any ambient, and the cell phone app will read the strip color. At this point it converts it into a number that specify hues and saturation, depending on the specific test being performed. This number can be sent directly from the app to a doctor that will be able to assess the situation and provide feedback to the patient.
What is good about this app is its simplicity and convenience of use. You don't need any training to use it, you have been practicing in taking photos with your phone for a while, haven't you?, so there is no problem in taking a picture. And then you can leave the rest to the app.