There are all sorts of explanations for why young adults don’t save as much money as they could or should. They graduated into a bad economy and don’t earn enough. They’re entitled Millennials who rely on their parents. They are drowning in college loans. And so on.

Maybe the answer is a simpler one: because almost everybody is bad at saving. And that’s not our fault. “Beyond a doubt, the human brain isn’t wired for the complex financial world we’ve created,” says Ethan Bloch, creator of a money-management app called Digit. Back when humans exchanged gold coins, you could keep track of your net worth by hefting your purse. In a world of digital transactions, however, you have “no real feel for what you’re spending,” says Bloch, who did research in behavioral finance at the University of Florida before embarking on a career that has included turns as a corporate accountant, personal finance video-blogger and founder of a social media marketing company. (It was called Flowtown and Demandforce acquired it in 2011.) Banks, which make $30 billion a year from overdraft fees, are just fine with that state of affairs.

Instead of rewiring the brain to be able to keep track of your wealth, Digit makes it so you don’t have to. Software monitors your checking account, keeping an eye on the pattern of inflow and outflow. When an algorithm determines that you have a little extra money you won’t miss, it sends you a text message asking permission to move it into a separate Digit-supplied savings account. It’s basically the equivalent of making sure those crumpled up dollar-bills and loose quarters in your pockets at the end of the day end up in your bank balance rather than in your dryer’s lint filter or between your couch cushions.

On average Digit users manage to save more than 5 percent of their income, says Bloch. That adds up to about $2,000 a year for the typical user. The company says it’s saving $1.3 million a week on behalf of its user base.

Since it makes its revenue from interest on the float, Digit doesn’t have to charge its users anything. Just the opposite, in fact: Through a new feature introduced this week, Digit will incentivize users to save by rewarding them with 50 cents for every thousand dollars they squirrel away and leave untouched for three months. Fifty cents may not sound like a lot, but it’s about 16 times they interest that some amount would earn at the biggest U.S. banks.

As my colleague Maria Aspan reports in the September issue of Inc., frustration with the archaic and predatory ways of big banks is fueling a wave of innovation in financial tech. Our brains may be bad at managing money, but apps like Digit suggest there may finally be more profit in helping us than in taking advantage of us. Says Bloch, “It’s a good time to be a consumer.”