In addition to several under-the-hood refinements to give it a more snappy feel, Global Delight’s Voila 3.6 offers improved performance and reliability when running in OS X 10.9 Mavericks. In particular, the screen capture utility no longer crashes while importing files under Mavericks, and it fixes issues with taking screen captures using an external display and the menu bar. Voila 3.6 also improves its Text tool, retools the video export functionality for Macs running 10.7 Lion and later, enlarges the knob markers in the Capture and Object tools, and adds a German localization. Normally priced at $29.99, Voila has been discounted to $19.99 through 31 October 2013, and there’s a further 25 percent discount for TidBITS members when purchased through Global Delight. ($29.99 new from Global Delight or the Mac App Store, free update, 20.7 MB, release notes)
Go Back and Forth Fast in Preview
If you're reading a PDF in Apple's Preview software, and you follow a bookmark or an internal link to move around within the PDF, you can quickly return to where you were by pressing the keyboard shortcut Command-[ (that's Command-Left Bracket). Or, you can choose Go > Back.
The command works iteratively, so you can go back to just the previously viewed page or if you issue the command again, to the page before that, and so on. There's also an equivalent Go > Forward (Command-]).