https://www.inaturalist.org/stats/2022/amybirder
https://www.inaturalist.org/observations?ident_user_id=amybirder&not_user_id=amybirder&place_id=any&verifiable=any

This tool displays which taxa you’ve seen that are least observed overall, and by extension can show if there’s any taxon for which you’re the sole observer: https://elias.pschernig.com/wildflower/leastobserved.html