Starter Story

I Built a $20K/Month App in 83 Days

Brian Shin and his girlfriend developed a mobile app called Once, a disposable camera app for events, which achieved over $20,000 in monthly revenue within 83 days of its December 2025 launch. Their success stems from a unique validation method called the "commitment metric," ensuring user commitment before writing any code. Once functions as a digital disposable camera for group events like weddings, birthday parties, and corporate gatherings. Its pricing is based on the number of guests, ranging from $2 for 10 people to $50 for 150 guests. The app currently boasts 10,000 to 12,000 weekly active users and has generated approximately $22,000 in revenue this month. Their internal dashboard shows over 300 events scheduled in February and around 700 for March.