optionsXpress - Options and Futures brokerage, now a subsidiary of The Charles Schwab Corporation.
Robinhood - Free stock trading service.
Entrade - Best Commodity Trading, Transaction, and Risk Management (CTRM)
Richie Invest - An app that lets you invest with your friends
Billion Operating System - Trading Application, Trading Software. Free Music Streaming Service
ClosingBell - Collaborative Stock Trading