There is an app for everything these days. And if you are current on your Infosec news you know every new app comes with its own vulnerabilities. One class of bugs has been relatively easy to find, with frameworks becoming increasingly available to help. But more and more developers are hardening their apps against common issues using jailbreak detection and best practices, and some of the easy issues are starting to dry up. Luckily for the top testers, there is another class of bug that can still (and only) be found with deeper knowledge of iOS and its underlying assembly code. The aim of this talk is to build a bridge between the mundane methodologies and vulnerabilities that everyone can find (and that are now being defended against), and a new approach that finds additional bugs that require assembly knowledge to discover. The talk looks at the fundamentals of reversing, a primer on iOS architecture, binary patching, reversing MACH-0 binaries, and ends with some real-world examples involving jailbreak detection. Attendees will leave with a better understanding of the reversing process as it applies to iOS, and each attendee will leave with a basic assembly-based iOS testing methodology.