The (specifically version V2.3 ) is a specialized utility application designed to interface Android devices with external USB inspection cameras, such as endoscopes, borescopes, and microscopes.
Uses "On-The-Go" technology to bridge the gap between a micro-USB/USB-C port and an external lens.
You can download the APK from the following direct server links provided by manufacturers: (Direct Download) CAMERA-AN97.apk V2.2 (Alternative Version) Key Details & Compatibility