YouTube Money Calculator - The easiest way to estimate YouTube earning potential
NumWorks - The graphing calculator that makes learning math easier.
Building Communities - A live class by Product Hunt's Erik Torenberg
Learney - Knowledge aggregator for developers
YouTube Community - A new, simple way to engage with your viewers
eMathHelp.net - Site is created to help people learn math. Includes algebra, calculus, differential equation calculators and notes with many examples.