How to use Acorns, the app that helps you easily turn your spare change into an investment portfolio

Acorns is an app that was designed for a single underlying purpose: to make investing a small decision instead of a big one, cofounder Jeff Cruttenden tells Business Insider.

Cruttenden wanted to make it easy for people, primarily those who were younger, to start investing a little at a time. To do that, Cruttenden built Acorns in a way that distills investing down to a decision of "how much" you want to invest and "how much risk" you want to take.

There are two ways you can invest money in Acorns. First, you can make a lump sum or recurring deposit. Simply select how much money you want to invest and transfer it from your bank. The second way is "round-ups." After you connect debit or credit cards, you can set Acorns to "round up" your purchases and invest the difference - if you spend $8.46 on lunch, Acorns will invest the $0.54.

Then you select how much risk you want to take, and Acorns invests the money into low-cost exchange-traded funds (ETFs).

Here's what it's like to use Acorns: