Mac: Little Snitch & LaunchBar 50% off ($17.48 & $14.50 USD)

From their Twitter Feed "Don’t miss the chance! @littlesnitch and @launchbar are 50% off today! #BlackFriday"

Little Snitch

Little Snitch informs you whenever a program attempts to establish an outgoing Internet connection. You can allow or deny these connections, or define rules to handle future attempts automatically. Little Snitch reliably prevents your private data from being sent out to the Internet without your knowledge.

LaunchBar

LaunchBar is a smart and powerful productivity utility that provides lightning fast access to applications, documents, contacts and bookmarks, to your iTunes Library, to search engines and more, just by entering short abbreviations of the searched item’s name.