Yank is built with Sonar Technology, Matterform's real-time file monitoring technology. Sonar uses the same technology that underlies Tiger's Spotlight feature. However, Sonar does not use Spotlight itself and does not interfere with Spotlight in any way.
Matterform also publishes a program called Sonar, which shows you file activity on your Macintosh. It is a useful troubleshooting tool and also provides an interesting peek at the surprising complexities of the Macintosh file system.
Yank includes a utility program called Sandal, which it installs in your Application Support folder. More info about Sandal is available on our Web site.