Robinhood - Free stock trading service.
TradeStation - Whether you trade stocks, ETFs, options or futures, TradeStation’s award-winning tools and...
Trigger Finance - IFTTT for the stock market
OptionsHouse - OptionsHouse is an online stock trading platform with an easy-to-use interface.
SysGears Grain Framework - The simplest way to start investing.
Questrade - Questrade IQ Mobile is everything you need to trade stocks - right in the palm of your hand.