Aged and Distilled has released Napkin 1.1.1 with stability and cosmetic updates related to OS X 10.9 Mavericks (see “Napkin Offers a Fresh Take on Visual Communication,” 16 February 2013). The image annotation and diagramming app fixes crashes related to opening documents with multiple imported images, dismissing the iCloud sharing dialog, and returning from redaction mode to a canvas with an arrow item. It also fixes a problem where an image item would draw the wrong content and bugs that inappropriately displayed an inverted canvas. ($39.99 new from the Mac App Store, free update, 8.8 MB, release notes)
Mac OS X Zip Expanding Utility
Firefox (and possibly other applications) may ask you what you want to do with .zip archives that you download from the Internet. If you want to expand them with Mac OS X (rather than StuffIt Expander), you may be unsure of which application actually does the job. You're looking for Archive Utility (in Leopard and later) or BOMArchiveHelper (in Tiger). In either case, the application is stored in Hard Drive/System/Library/Core Services/. Don't move it from there, though, or you'll confuse matters.