MentorCruise - Personalized mentorship experiences
On-Screen Ruler - lightweight, free, semi-transparent ruler
Exponent PM Interview Course - Interactive product management interview practice & coaching
Bluegrams Screen Ruler - A lightweight and configurable ruler tool for Windows Desktop.
Product School - The global leader in product management training
Pixus - Pixus is an AIR pixel ruler application, a handy tool for web and interface designers.