Please edit this page if you are Trust Level 1+ to add broken or unmaintained plugins or features no longer working in current Stable release. This is not a thread for complaints. 
18.0.4
[App Name](www.github.com/example/app-repo/)
Social - Needs rewrite for version 18
Bookmarks Full Text Search - broken a couple releases now
Unmaintained Apps - No Updates in 2+ Years
Paper - broken since 13. Save offline copies of websites.
mood - Discontinued in favor of Social app.
Nextnote - Nice notes application with same user interface as Evernote. Ahead of it’s time!
dms Dead Man Switch, for publicly releasing a file after x amount of inactivity.
Sign on from Wordpress - also discussed in this forum thread.
Report App Specific Breakage
Include GIthub links if possible.