Brett Terpstra has released Marked 2.3, which sandboxes the Markdown previewer in order to bring it to the Mac App Store. While Marked 2 replaces the original Marked app in the Mac App Store, Marked 2 is not a free update — though it is on sale for $9.99 for a limited time (both from the Mac App Store and the Marked Web site). The update now supports GitHub Flavored Markdown for the app’s Discount processor option, preserves bookmarks across refreshes and style changes, adds highlight navigation and highlighted word counts, fixes a problem with reading the most recent file in a folder, improves handling of unreadable and renamed files, and fixes an issue with initial file monitoring when opening in an external editor. Because Marked 2 is sandboxed, previously opened documents may require new permissions. Marked 2 doesn’t currently support OS X Yosemite, but Terpstra promises it will be added soon. ($9.99 new on sale for a limited time, free update, 16.7 MB, release notes, 10.7+)
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-]).