No, it's not merely to report the ping, ping, pinging of sleet pellets on your window, but PING in this instance stands for Precipitation Identification Near the Ground.
Volunteers would sync their phone to their GPS to provide a real time location and then submit reports based on what's falling overhead at a given time. The project relies on volunteer providers to report snow, sleet, icy rain, rain, or some combination thereof by selecting "select precip type" and then submitting the report.
Comments can't be included via mobile technology at this point but if you want to refine and add information to your observations the PING project managers will accept them via email.
The app is free and available on both Google Play and on the Apple app store.