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+)
Compare More Easily in Apple Mail
In Apple Mail, if you need to work back and forth between two different views of Mail's mailbox contents, you can do so quite easily. For example, you might want to look at a mailbox holding all filtered-in sales orders from the past week while also looking at a smart mailbox showing unanswered customer questions.
To avoid constantly clicking between mailbox views and losing your context each time, choose File > New Viewer window to get a second window and then arrange each window as desired.