Robinhood - Free stock trading service.
StockTwits + Robinhood Integration - Zero commission trading directly from the StockTwits app
Ellevest - An investing platform built for women
StockTwits for Slack - Fun, real-time stock quotes in Slack
Alpaca Data API - Free real-time stock market data API
CNote - 40x better returns than the bank. Help savers earn more