Robinhood - Free stock trading service.

Riskalyze - Riskalyze is a quantitative system for identifying client risk tolerance, aligning portfolios to client expectations, and quantifying the suitability of investments.

invstr - Investing for everyone (with fantasy $$$)

CXi-Registry - CXi-Registry is a fund administration software that helps an investor registry streamline and automate its back-office work.

M1 Finance - M1 helps you manage your money by automatically putting it to work in a customizable portfolio

Backstop Solutions - Backstop Solutions Group provides CRM software suites for investment managers, portfolio managers, hedge funds, funds of hedge funds, endowments, pensions, and more.