19-Year-Old Sold His AI App for $30M at 19: Now He's Trying To Break Gen Z's Worst Habit

Zach Yadegari was 19 and halfway through his first year at university when he sold the calorie-tracking app that had made him a millionaire. He gave himself almost no time off before starting again, this time aiming at a habit familiar to most of his generation: doomscrolling.

The teenager from Long Island, New York, co-founded Cal AI in high school with his friend Henry Langmack and grew it into a business turning over around $30 million (£22.5 million) a year. Fitness platform MyFitnessPal bought the app in December 2025, Business Insider reported, on terms that were not disclosed. Cal AI, launched in May 2024, passed 10 million users, logging meals from a single photo rather than manual entry.

Stepping back did not suit him. 'I was trying to enjoy life for the first time without the stress of running a company, but I got bored extremely fast,' Yadegari said in the first episode of a YouTube series documenting his next company.

From Early Wins to Cal AI's Rapid Rise

Cal AI was not his first exit. He founded an unblocked gaming website called Totally Science at 13 and sold it at 16 for $100,000 (£75,000), then put the proceeds into the calorie app. Cal AI estimates calories and nutrition from one photo at roughly 90% accuracy, and scaled fast enough to attract a buyer that had led the category for more than a decade.

MyFitnessPal kept the small Cal AI team after the deal closed and folded the app into a nutrition database of about 20 million foods, while Cal AI continues to run on its own.

Yadegari, who reported a 4.0 grade average and a 34 ACT score, was rejected by 15 of the 18 top universities he applied to, among them Stanford and the Ivy League, and now studies at the University of Miami.

Crackdown on Gen Z's Doomscrolling

His new brand, Flow, is built around the problem he says he could not shake. 'Flow is a bigger brand that will have multiple products under it,' he said. 'Our first product is the Flow alarm clock.'

The device pairs a small dock with an app. The alarm rings on the phone and will not stop until the user gets up and taps the handset on the dock, which also unblocks any apps set to be locked overnight.

'You actually have to get up, get out of bed and go there,' he said. 'So, no more doomscrolling.'

The idea took shape after the sale, when he set out to build a physical product rather than another app. He said he had noticed that screen-time gadgets such as Brick blocked apps but had no alarm function, so he combined the two.

The economics are far less settled than at Cal AI. Yadegari said he put $200,000 (£150,000) of his own money into Flow and had spent $150,000 (£112,500) within months, leaving about $10,000 (£7,500) in the bank before he injected a further $100,000 (£75,000). He said the brand was running at roughly $300,000 (£225,000) a month, short of the millions he is aiming for.

His route to profit borrows from Cal AI. Yadegari said the plan is to sign up as many subscribers as possible, break even on the first sale and earn the margin on later renewals. Flow sells the dock with an optional subscription, and he ran a pre-sale before the first units shipped, taking payment while warning buyers their orders would take time to arrive. Marketing runs largely on Meta ads and a network of affiliate creators.

The shift from software to hardware has been the hard part. The first docks took around three months to manufacture, customer acquisition costs have swung sharply, and recent sales have hovered around, and at times below, break-even, he said. The series in which he is laying all of this out is titled 'How I'm Building a Billion Dollar Company.'