If you understand what you're signing up for and still want to dabble in stock trading for fun then sure. Go wild. Everyone needs a hobby. But the homepage of robinhood.com has the following call to action above the fold:

> Investing, Checking & Savings. All for Free.

> Robinhood gives you the tools you need to grow your savings, invest in your future, and do more with your money.

Does that sound like "this is not an appropriate way to finance your retirement" to you?