This is the Google Camera for Essential Phone based on Arnova8G2's MGC_6.1.021_V1d-Advances_test2.apk.
Google Camera APK is a Camera app for Android devices typically only available for Google Pixel device. But there is a Google Camera APK port available for almost every Android phone out there which is ported by some developer.
Other Google Camera (GCam) APK Downloads:
- GCam APK Download (The huge list that contains working GCam ports for all available phones)