The App I Built In 12 Hours Makes $15K/month

Frustrated after 15-20 mostly failed tools, he built 4-5 tiny tools in one week on his personal website's home page, sharing each on Twitter as he built it. AudioPen's MVP, built within a 12-hour Halfday Build hackathon (start at noon, aim for $1 of revenue by midnight), got much more attention than the others, so he built a full version with a price tag. His advice: build small things you can shut down without hurting users; the cost of experimentation is low, so build a bunch and double down on what resonates.

When the prototype got signal on Twitter, he DM'd the people who liked it and asked why; a few explained their use cases. He then designed for those use cases in Figma (using Pinterest for inspiration) before building the full version.

About 10 hours into the 12-hour build he launched a waitlist so people could sign up before the tool was ready, and let early beta testers use the product with full access. Several paid through Stripe before the 12 hours were up even though he had only asked them to test. Advice: if people resonate with what you share, spin up a quick email list, even a Google Form, and launch the simplest version as early as possible.

He had built in public on Twitter for months to years before AudioPen, building credibility and hype before the product existed; members of his Halfday Build hackathon community cheered him on publicly, which he believes helped buyers trust him. He deliberately presents as a solo indie builder rather than a big company, sharing his story and the effort behind the product. Advice: share designs publicly, see what people like and don't like.

AudioPen does one thing: voice to clean text. He was tempted to expand into adjacent markets where apps were doing well, but consciously stuck to doing the simple thing well, while competitors tried to do too much.

Free version gives a taste with a shorter recording limit. Paid ('Prime') unlocks ~15-minute recordings, writing styles, integrations with other apps and more. Paid plans are $99/year or $159 for 2 years, both non-recurring: users control whether to renew at the end of the term.