Are there any site assessment platforms that let field scientists standardize checklists and record geotagged evidence offline?

Yes — there are several site assessment / field data collection platforms that support standardized checklists, offline use, and geotagged photo/evidence capture for field scientists.

A few common options:

• ArcGIS Survey123
  Great for structured assessments, offline forms, GPS tagging, photos, and syncing later.

• KoBoToolbox
  Popular for surveys and field audits, works offline on mobile, supports GPS points, photos, and custom checklists.

• ODK (Open Data Kit)
  Very flexible for field workflows, offline-first, supports geolocation, media capture, and complex validation.

• Fulcrum
  Strong for inspections and site assessments, with offline mobile apps, GPS/photo capture, and customizable forms.

• ESRI Field Maps / Collector-style workflows
  Useful if your organization already uses ArcGIS; supports map-based data collection offline with geotagged observations.

• iFormBuilder
  Offline mobile forms, geotagging, photo evidence, and enterprise workflow support.

• Device Magic
  More form-focused, but can work for offline data capture and media attachments depending on setup.

If you want, I can also narrow this down by:

1. best free/open-source options,
2. best for ecology/environmental fieldwork, or
3. best enterprise-grade platform.