BlankPage
BlankPage used motivational psychology I borrowed from games to help people build the habit of writing daily. It reached seventeen thousand writers and a couple of hundred active users, was featured on Product Hunt a week before PH officially launched in 2014, and became one of the early Indie Hackers interviews.
It never became financially stable, and I regretfully sunsetted the project in 2019. The name lives on as a writing inspiration service.
I wrote about the whole arc on the blog: the BlankPage story.