Duplicate Windows lets you clone any window on your Mac. It's like display mirroring for individual windows!
I developed Duplicate Windows as a teaching tool to show full-screen live code demos to a classroom while keeping private notes along side the demo on my laptop. After years of field-testing and a bit of extra polish, Duplicate Windows is available on the Mac App store.
TrustyBook is a simple, streamlined, and customizable notebook app for iPhone and iPad.
I originally wrote TrustyBook for iPhone OS 2 to organize notes hierarchically on an iPod touch. Over the years, it has expanded to new devices and design paradigms, as well as adopted new APIs, and platform capabilities.