The first major crowdsourced science project I remember is SETI@Home, which uses computers processing power while they ‘sleep’ in order to analyze radio telescope data. Now that phones have comparable computing power, it makes sense that some have decided to take advantage of that power when they sleep.
Thanks to Alexis Madrigal and his 5 Intriguing Things, I learned about CRAYFIS. The project name – Cosmic RAYs Found In Smartphones – is pretty straightforward. Using a large network of smartphones, the project staff intend to find high energy cosmic rays without investing in a large custom detector. All participants need to do is download the app, connect the phone to a power source when it goes to sleep, and keep it face up. Using the phone’s GPS information and CMOS sensors linked to the phone’s camera, the application can detect the byproducts of high-energy cosmic rays. You can read the technical paper on the project for more details.
A key to success for this project is ensuring enough phones are participating in the network. Per the technical paper, this appears to be at least 1 million phones. Not an easy task, as far as I can tell. At present the only incentive appears to be author credit on any papers resulting from data collected by a participant’s phone. CRAYFIS is currently in beta testing, so if you are interested in participating, leave your contact information on the project website, and they will be in touch.