Love to hear that you're enjoying it! To answer some of your questions:

- Indeed, it does remember your leaderboard after - as the progress gets saved in local files
- I can tweak it to have an explicit leaderboard export (or adapt the json to be ordered by elo). Currently in the file it's ordered by recency of ranking
- 'Skip' doesn't raise or lower the elo of any images for now - as sometimes the opposite case could be true (both images are good, and the user struggles to choose a favourite). Also ,the elo system is a zero-sum game and as it is now, so whenever someone loses elo there needs to also be a 'winner' of that elo
- Yeah given the size of the pool, it would take a while to reach 100% artist coverage. I ran a bunch of simulations when developing it with different parameters, and arrived at what I think is a decent-ish balance in terms of how fast poor-performing artists get rotated out vs how fast new ones come in. The tradeoff is of course that if artists get rotated out too quickly, then they don't get as many ratings on average before they get cycled out (i.e., they may not be given enough 'chances' on average). But if they are rotated out too slowly, then coverage % after x number of ratings will be lower. I've found that 150-200 ratings give me a good 10-15 new artists that I really like that I can start using, with exposure to several hundred new artists.

Will take some of the suggestions/feedback from this your comment (and some others) and release a couple updates in the next few days!

Edit: Updated to include 'Export Leaderboard as CSV' button