How I built a $30K/month mobile app | Starter Story

John McAvoy, a self-taught developer from Scotland, built a mobile app that has been downloaded over five million times and now generates roughly $30,000 per month in revenue. He did it alone, without spending a cent on paid marketing. The entire growth engine was App Store Optimization (ASO), a strategy he describes as "really just about research and patience." In this conversation with Pat Walls on Starter Story, McAvoy walks through how he found the idea, why he chose to build it, and the specific, repeatable process he used to get millions of downloads for free.

The Idea: Solving a Personal Problem with a Clear Niche

McAvoy did not set out to build a business. He had a personal frustration: he wanted to track his golf handicap, but the existing apps on the market were either too expensive or too cluttered with features he did not need. "I had a problem I needed to solve, so I built it," he says. That is the entire origin story. He was not looking for a scalable startup idea or a venture-backed opportunity. He was looking for a tool that worked the way he wanted it to work.