Fidelity has improved its mobile app in the past couple of years, and while they do have separate apps for research or robo-advisors through Fidelity Go, they are easy-to-use and offer amazing charting tools. StockTwits — Stock M Plus Online Tradi How it works: Users share posts, organize streams, tag others and can even connect their StockTwits and Twitter account. Whether you decide to play the market as a bull or just want to buy and hold, stock trading apps have made investing extremely popular.