Startup School - How to start a startup, by Y Combinator
Awesome Cal - Awesome Cal is a Calendar application for your iPhone that you can take anywhere and keep close by to monitor all the upcoming birthdays, festivities, meetings, and more from a single place.
YC World - Explore Y Combinator companies by country
24me - Next Generation Personal Assistant
Y Combinator Companies - Interactive list of all 1000+ YC companies
Calvetica - The fast calendar for iPhone. Add an event in just two quick taps.