Platform: Mac OS X
Technology: Swift
Current Status: Actively Developed keeps tabs on GitHub pull requests across repositories, directly in OS X Notification Center, started as a part-time project at HouseTrip and released as open source under the MIT license.

What can it do for you?

Link with your GitHub account quickly & easily by creating a GitHub API token, paste it in the settings window and you're ready. 

Includes "Your Own" / "Participated" / "Merged" / "All PRs" sections. 

Integrated with Notification Center to keep you notified of comments and merges. 

Search / filter PRs on-the-fly by typing. 

Clicking on a PR or comment opens it on GitHub.

View PRs only from repositories you are interested in.

Menu item turns red when you have unread comments & places badges in the PRs on your list.

Official page: