Solo founder built a $50K/month app with this exact tech stack: Jake is 24. He launched Erly (an alarm app where you do pushups to turn off the alarm) at the end of 2025 and hit $50K/month in 4 months. 200K+ downloads. One-man show. Here’s the full stack he runs it on: Firebase for database, auth, cloud functions Superwall for paywall + subscriptions OpenAI for the AI API Mixpanel for in-app analytics Claude Code for actually building the app Heroi for influencer tracking + payments Sideshift for UGC creator sourcing Instantly for mass influencer outreach Cal for booking, Agree for contracts QuickBooks + 1Password + Google Sheets to run the business