Im not sure about the “near instant” part.

A new smartphone app developed by a Clemson researcher is designed to aid coroners and forensic teams in determining time of death by improving the understanding of body decomposition. The app allows users to enter observations, photos and other information related to geography and crime scene data when uncovering human or animal remains. After years of use, app developers hope the data collected will allow a near-instant estimate of time of death in the field.
— Read on newsstand.clemson.edu/mediarelations/app-created-by-clemson-researcher-uses-photos-of-dead-bodies-roadkill-to-help-forensic-teams-determine-time-of-death/