Who Said That? - A game where you guess who tweeted what
Startup School - How to start a startup, by Y Combinator
Retro Clicker Arcade - Simple one button clicker arcade
Apply to YC (Y Combinator) - Curated collection of resources for founders applying to YC.
Breakout List - A list of the fastest growing startups
YC World - Explore Y Combinator companies by country