How We Built It: $85K Mobile App | Starter Story

Jack Sweeney and his brother Nick built a mobile app called Coherence that has generated $85,000 in revenue with over 15,000 downloads in eight months. But the striking detail is that Jack, the non-technical co-founder, never wrote a single line of code. The brothers did not start by building software. They started by making content about breathwork and nervous system regulation on X, Instagram, and TikTok. Only after they saw which posts went viral did they build an app around those validated ideas. Their story is a case study in using content as a market research tool before committing to product development.

The Content-First Validation Loop

Jack and Nick's core insight was that content could serve as a low-cost, high-speed way to test whether an idea had real demand. Jack, who had a background in YouTube content creation, began writing threads on spiritual and esoteric topics. Nick, who had recovered from a severe injury through breathwork, posted about breathwork and nervous system regulation. They used X as an "idea battleground" — posting short pieces of content and watching which ones got traction. When a post went viral, they would turn it into a short-form video script for Instagram and TikTok. If that also performed well, they would expand it into a longer YouTube video. This "moving upstream" approach let them validate demand at each stage before committing mor