Theory A is described as 'Stock value screener that make values investing easy and accessible and visualizing fundamental value signals such as Price to Earnings, Price to Sales, and Price to Book. It is based on the strategies outlined in the national bestseller "What Works on Wall' and is a Stock Trading app in the business & commerce category. There are more than 10 alternatives to Theory A for a variety of platforms, including Web-based, SaaS, Android, iPhone and iPad apps. The best Theory A alternative is Koyfin, which is free. Other great apps like Theory A are Charted Market, QuantLink, FinViz and Candulux.