The Loss of the Night app allows citizen scientists to estimate how many stars they can see, and by extension how bright the night sky is. The goal of the project is to track changes in artificial sky brightness in urban areas over the long term (ideally many decades). The app is available for Android and iOS devices. Detailed instructions for using the app are available (Android, iOS).
The day after you've made an observation, you view the details of your observation at the My Sky at Night website. You can also use My Sky at Night to track how skyglow is changing at your location over time.
This blog posts news about the app, and is intended to allow the app users to provide feedback on how we can improve the app in the future. For example, check out this example of one participant's observations. I also do post occasionally about other topics related to artificial light at night, for example this ongoing photo series of examples of good and bad lighting, and views of the night sky.
The Loss of the Night app project is operated in co-operation with the Globe at Night project.