I Built a $20K/Month Mobile App: Here’s My Entire Playbook

Developed the app in three days using Cursor and ChatGPT, despite having a finance major and almost no programming experience.

Prayer Lock is a straightforward app that locks phones and unlocks them by reciting AI-generated prayers, with a subscription model of $49.99 annually or $9.99 weekly.

Achieved approximately 58,000 downloads, 6,700 reviews, and a 4.9-star rating in six months, with an astonishing conversion rate of 43%.

Initially posted 40 times a day across 12 different accounts, eventually achieving a viral hit with UGC (user-generated content) style female reaction videos.

After success with TikTok organic posts, experienced failure with Meta ads but re-attempted after improving onboarding from 5 minutes to 15 minutes.

TikTok Spark Ads were particularly effective, acquiring trials at a cost of $3-4 per trial start, yielding a high ROI against the $50 annual subscription.

Discovered a 15-year-old UGC creator named 'Matthew' and achieved further growth by leveraging his videos in Spark Ads.

Maintained a monthly growth rate of over 50%, with $10,000 in October, $15,000 in November, and $21,000 in December.

The tech stack is very simple, including Cursor, ChatGPT, Google Gemini Flash 2.5, and AWS, with monthly costs remaining under approximately $100.

Ad spend is $360 per day (approximately $9,000 per month), with a cost per trial of $1.88, resulting in a healthy profit margin.