This is mobile application which has been written using React Native to easily browse camera events of Frigate NVR. This is not official app.
Follow the instructions of React Native docs to install Android Studio and the emulator.
Run npm install to install dependencies and npm run android to start the emulator, compile the app and install it on the emulator or a connected device.
google-services.json file should be placed in ./android/app folder - it should contain credentials to Firebase for Crashlytics service.
I've never run this application on iOS. It should work in theory, but probably needs some enhancements.