He turned a simple idea into a $15K MRR mobile app | Starter Story

When Sebastian Rowl quit his job with no plan and no idea, just twelve months of runway, he figured he'd build something. Six months in, he had fewer than a dozen downloads across all his apps. "I was just building things I thought were cool," he says. "But nobody else thought they were cool." Then he changed his approach entirely—and within two years, he was making $15,000 a month as a solo developer with an app that had been downloaded over 300,000 times.

The failed experiments that taught him what not to build

Before hitting on what worked, Sebastian built several apps that went nowhere. One was a habit tracker where you'd set a goal and a friend would verify you actually did it—social accountability, in theory. "It was a cool concept," he says, "but nobody used it." Another was a "digital detox" app that let you set screen time limits and lock yourself out of apps. That one got maybe 50 downloads total. A third was a journaling app with a twist: it would ask you questions about your day and you'd answer by tapping emojis. "I thought it was genius," he recalls. "But people don't want to journal with emojis."

The pattern was clear: he was building for himself, not for a market. He was solving problems he found interesting, not problems people would pay to have solved.