Not long back, I joined a GitHub organization at work and discovered that being added to the organization had automatically added every repository to my watch list.
This wouldn't have been so bad, but this particular organization had over 160 repositories! After getting a raft of emails over a couple of days (every time someone updated anything…), I went into my account settings and discovered that GitHub only allows you to unwatch one repository at a time.
If you find yourself being annoyed by floods of repo update emails, this might be the app for you!
Hope it comes in handy!