see https://forum.inaturalist.org/t/check-out-this-cool-inaturalist-streak-finder/3076
i don’t think ether of these exist currently, but you could use the API to figure these out. the first step for each of these is probably to get your observation counts by day. here’s a page that can get you this information for this first step in a human-friendly format: https://jumear.github.io/stirfry/iNatAPIv1_observation_histogram?user_id=yayemaster&interval=day&created_d1=2010-01-01&date_field=created
i’m not sure what “missing” in this context means exactly, but i’m sure it’s possible to figure this out by doing some sort of comparison between your species and some sort of reference list of species. depending on what your reference is, there may or may not be an existing tool to get this information.