I just published my newest open source library at https://github.com/ooples/OoplesFinance.YahooFinanceAPI and this is a fairly simple API that allows you to scrape stock market financial data from Yahoo Finance. I have personally used this code in my personal projects for quite awhile so I figured I would make it public.
And of course my stock indicator library is available at https://github.com/ooples/OoplesFinance.StockIndicators