Robinhood - Free stock trading service.
State.of.dev - Visualizing the current state of development
Autocode - Build app-to-app API workflows with automatic codegen
Quantiacs - Earn money by creating trading algorithms in your spare time
Matador - Free investing + Social feed of trades + 2.5% on your cash
Algorithmia - Algorithmia makes applications smarter, by building a community around algorithm development, where state of the art algorithms are always live and accessible to anyone.