Of course, it only had a 3 month shelf life, but I still made about $50k from it. I think the app peaked at #5 or #6 on the top 10 paid apps list and I was making about $1,000 per day from it then.
Fun fact: the data that powered the app was sourced from https://electoral-vote.com, which is operated by Andrew Tanenbaum, the creator of Minix.