App turns a smartphone into a pocket-sized cosmic ray detector

There are all sorts of apps available for smartphones to show atmospheric phenomena like wind speed, temperature, and rainfall, along with other observations for tides and phases of the moon. But how about something really cool like an app for measuring the amount of interstellar cosmic radiation hitting the earth?
A professor of physics from the University of Wisconsin thought that would be cool as well, and created an app to turn your smartphone into a cosmic ray detector that works in a similar way to those instruments found in high-tech observatories and mega-expensive laboratories.
Thought to be created in such things as black holes and stars that go supernova, cosmic rays are high-energy subatomic particles that are spewed out across the galaxy at tremendous speeds. When they hit the atmosphere of the Earth, they are smashed apart when they collide with molecules such as oxygen and nitrogen, where they breakdown into such things as x-rays, electrons, neutrons and charged mesons.
These charged mesons then further decay into muons. Many of these muons then make it all the way to the ground and, as a result, they can then be detected. From there, extrapolations can then be made as to the amount and intensity of the cosmic rays that produced them.