Simple timer app makes $25K/month. How? | Starter Story

Lucas, a solopreneur from Germany, built a simple countdown timer app that now generates $25,000 per month in revenue. The app, called Countdown Timer, does exactly one thing: it lets users set a timer that counts down to a specific date and time. No notifications, no alarms, no calendar integration — just a visual countdown. In this episode of Starter Story, Lucas explains how he turned a "stupidly simple idea" into a business that allowed him to quit his job, why he hired his wife to help run it, and his framework for finding more ideas that can generate thousands per month.

The origin: a Reddit post with 58 upvotes

Lucas did not start with a grand vision. He was working as a software developer in Germany and wanted to build something small on the side. His criteria were specific: the app had to be simple enough to build in a weekend, solve a real problem he personally experienced, and have no existing good solution. He noticed that when he needed to count down to an event — a vacation, a deadline, a birthday — every existing timer app was either too complicated (full calendar apps) or too noisy (apps with alarms, notifications, and ads). He wanted something minimal: open the app, set a date, and see the countdown.