Stash is an app for iOS and Android that makes it easy to start investing, even if you don't have a ton of money. Stash does charge $1/month, but the first month is free.

You can start investing with as little as $5!

Staff writer Jamie Cattanach says Stash even explains investing in terms you can understand. She set up Stash to automatically pull $5 per week from her bank account to invest and build her emergency fund.