As cool as an mobile-friendly Identify page would be, I have a feeling a dedicated ID app would probably be the best solution since the current Identify page is pretty heavy, resource-wise.
I believe the two types of pages commonly linked to from the app are taxon pages (from the basic taxon info screens in the app) and observation detail pages (if you use the share button) so I would personally want to prioritize those, especially the taxon page since is has a lot of good info and is less interactive than the observation detail page.
(Observation detail is our term for an observatiton’s page, eg https://www.inaturalist.org/observations/25424950)