The Y Combinator Database - The definitive database of YC companies with all the metrics
Finimize - Financial news explained in 3 minutes in a daily e-mail
Startup School - How to start a startup, by Y Combinator
Scout Finance - Free finance app that's like having a Bloomberg in your pocket. Download:
Y Combinator Companies - Interactive list of all 1000+ YC companies
Robinhood Snacks - Your daily doze of financial news