You’ve probably heard of Digit, the free mobile tool that analyzes your spending habits and stows away small amounts of cash to a savings account.

Founded in 2013, it’s been able to remain free because it keeps its users’ earned interest as a source of revenue. But while Digit has saved about a quarter of a billion dollars for its users, CEO Ethan Bloch says the company has earned only “a tiny amount” in the current interest-rate environment.

In order to one day become a profitable business, Digit plans to start testing new revenue models soon. This means the tool may not stay entirely free. “As we continue to build the product, our goal is to probably charge for premium services that we offer,” Bloch says.

Watch the video above to hear Bloch’s plans for the future of Digit.