I collect vintage Pokémon cards, and they can be surprisingly difficult to track down. More often than not, the one card I was hunting for only showed up as part of a big bulk lot someone was offloading. By chasing cards for my personal collection from old box sets and starter decks, I gradually accumulated a huge stack of "extra" cards. What began as casually selling those extras on the side turned into something bigger: before long I had an inventory of more than 1,000 cards and realized I needed a much better system to keep everything organized and running smoothly.
Each individual card required:
its own listing with the correct name, set, edition, condition, plus clear photos of both the front and back;
a description that would actually make sense to a potential buyer;
and at least one or two social posts, because otherwise only people already searching for that exact card would ever find it.
The cards themselves were the enjoyable part. But handling them one by one, across hundreds of listings, quickly turned into an unintended part-time job. I also realized that social posting was always the first task I dropped when things got repetitive, which meant cards would be technically listed and live, yet practically invisible to anyone who wasn't already looking for them. A listing that nobody sees doesn't move, especially with collectibles, where most of the interest comes from social feeds and fan communities rather than the marketplace search itself.
So I created a Mac app that automates the entire workflow from start to finish and publishes listings to my own website. Here's how I approached it: The thing about Pokemon card collectors (and why I needed a simpler…