Hi Eli,
This is a commonly encountered problem for iOS at the moment that is being investigated, so I’m going to close this report. One solution at the moment that seems to be working for a lot of people (including me) is to delete the app and reinstall it. If that doesn’t work, please add a comment (including your app version, etc) to one of these exisiting threads:
https://forum.inaturalist.org/t/app-freezing-ids-taking-photos-etc/16871
https://forum.inaturalist.org/t/ios-app-crashes/16178/