I thought I would share my project that I just finished working on. It is a web enabled air particle sensor. It is designed to be built by high school students as a citizen science project. It took a bit of work to design something simple and cheap that required no soldering or technical skills,
The instructions can be found at http://www.instructables.com/id/Photon-Air-Particulate-Monitor/
There is even more info at my website https://airquality406.wordpress.com/