Beacon is a an open-source social network and accompanying Android app that allows you to anonymously share interesting things and events with people in your local community. Beacon is still in active development, but when finished, using Beacon will be something like this:
Users take a picture in-app. Beacon takes a geotag and posts it on the map. Beacons that are more popular are indicated on the map. You can select a beacon to see what people are saying about it and to add your own comment.
Beacon was started as a university project and as such, is not currently open for pull requests. In January 2016, however, Beacon will become open for contributions.