Fixing bugs in UIKit, inspecting 3rd-party apps using Reveal and doing advanced stuff with lldb. My talk for Mobile Central Europe in Warsaw, Poland.
Quite some is lost without the videos and comments - MCE should release the recording of my talk some time in February.
Resources:
UIPrintViewController: https://gist.github.com/steipete/8255790
PSPDFTextView: https://github.com/steipete/PSPDFTextView