Like the Android version, it uses GPS and allows fisherman to upload photographs of their catches. NOAA says:
The app uses a device’s built-in GPS, when available, to fill in exact location coordinates on the shortfin mako live release data form. The catch and release reports submitted via email allow fishermen to put their mako on the Live Shortfin Mako Releases Interactive Web Map
The submission form is easy to fill out and operates like the online submission form. Touching the latitude and longitude boxes provides an location when GPS is available. The app also includes information about shortfin mako stock status, fishing regulations, FAQs, and safe handling and release guidelines.