Developers building iOS 7 apps may want to download Typeset by MartianCraft, a free app that lets you preview iOS 7 system fonts side by side. Typset includes layout cards for previewing how fonts look in various configurations, tools for adjusting line spacing and font sizing, and the option to mark saved sets as favorites for later browsing. A $5.99 in-app purchase unlocks Typeset Pro, which enables the option to export the end result as a predefined stylesheet or PDF. Download it from the App Store.