Medicine has several unanswered questions regarding Parkinson’s disease, Alzheimer’s, diabetes and other chronical diseases. Researchers might understand them better if they were able to track the day to day symptoms of large numbers of patients. Smartphones, and other mobile devices offer a way to do so. Equipped with sensors, accelerometers and ' GPS, they can record movement and exercise. Apple’s new watch, announced last week,' measures its wearer’s heart rate and can work out whether he is standing, sitting ' or going up or down the stairs. This week Apple introduced an open source software pack, the ResearchKit, which will make it ' easier and cheaper to create scientific apps that work with its mobile devices, reports the Economist. The mPower application being developed by the Fox foundation provides data on the actual state of people with Parkinson’s. It measures someone’s finger-tapping on an iPhone’s screen in order to detect inconsistencies in rhythm. The accelerometer studies gait and balance while the user is walking. Its microphone can help detect minute fluctuations in his voice. For further details read the article on The Economist online.