A stock trading app is simply the software you use to buy and sell stocks and other securities through a brokerage. Webull (for instance), allows not just taxable brokerage accounts, but also tax-advantaged traditional IRAs and Roth IRAs. If your preference is for long-term investing only, you should also focus on a platform that offers fee-free mutual fund trades as well, which you can pair with ETFs (or use them on their own) to build a diversified set of holdings.
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