Feedcritic helps you keep track of the many podcasts you're subscribed to and choose which episodes to listen to. I'm playing around with code at https://github.com/pdurbin/feedcritic (includes screenshots) which has been deployed to http://podcasts.greptilian.com
Pastries is a quick and dirty HTML5 game that could be cleaned up and used in a tutorial for kids writing their own games: https://github.com/pdurbin/pastries
Druthers allows for crowdsourced issue ordering. https://github.com/pdurbin/druthers contains proof of concept code. To see me mentioning the idea to a user asking about particular issues, see http://irclog.iq.harvard.edu/dataverse/2017-03-01#i_49428
Connectors allows you to describe the relationships between people you know and where they hang out online. There is a some proof of concept code at https://github.com/pdurbin/connectors and an example based on IRC channels at http://irc.greptilian.com
Outsiders would allow you easily filter your GitHub issues down to the ones that weren't created by members of the project. An example query would be
is:open repo:pdurbin/addressbookmvc -author:pdurbin -author:dhutty.
Unread monitors your WeeChat hotlist and provides a link to the public logs of an IRC channel so you can catch up in a browser when you don't have access to your screen session. There's some very rough code at http://unread.greptilian.com that needs to be cleaned up.
Clipshare would allow you to pause the podcast you're listening to and share a clip that you find particularly interesting. See also a related discussion in the AntennaPod issue tracker.
CopyAddressToClipboardAndTitle (CATCAT) would be a Firefox add-on that copys the address (URL) and title of a web page to the clipboard. It would be useful for GitHub Issues, Twitter posts, news articles, and more. Previously I used CoLT for this purpose but there hasn't been any movement on https://github.com/jgbishop/colt/issues/16 so maybe it is time to start a new add-on, perhaps using https://github.com/def00111/copy-link-text as a starting point.