In 2023, I tried my luck with four different educational apps, but none of them really made any money. Then, while working on an English learning website, I added a simple feature where users could chat with AI. Surprisingly, this became super popular!<p>This got me thinking: why not create an app that lets people practice speaking English with AI characters? I put together a basic version of the app in a month and shared it on voz.vn, a well-known forum in Vietnam. The app got 500 downloads on the first day alone, though I didn't earn any money from it initially.<p>In the next 3 months, I only made around $50. But I think the app had potential, so I kept working on it. I improved the design, fixed some bugs, and added more languages like Chinese, Korean, Spanish, French, Japanese, and German to attract more users.<p>The game-changer was in December, 2023 when I got a popular Youtuber to promote FluentPal. That move really paid off, and the app took off.<p>Now, FluentPal earns $3,000 a month, with half coming from subscriptions and the other half from lifetime package purchases. A lot of B2C users prefer buying the lifetime package because they only want to pay once.<p>That's the story of my app.