Proof.ink - Proven immutable data stored on the Steem blockchain
Robinhood - Free stock trading service.
Immutable.js - Immutable persistent data collections for Javascript which increase efficiency and simplicity. - immutable-js/immutable-js
TradeStation - Whether you trade stocks, ETFs, options or futures, TradeStation’s award-winning tools and...
DataTip - The fastest way to store & access your critical datapoints.
OptionsHouse - OptionsHouse is an online stock trading platform with an easy-to-use interface.