Google Camera is the same application that comes with Google Pixel (Google's smartphone), and those who have used one of these devices or have been following the samples taken with them know the quality it offers. Now any One can simply download this app on another compatible smartphone, thanks to a Ukrainian developer who started the project and gave us access to the APK.
In order to improve photo quality, unlock new features, fix bugs on their phones, support new ones, etc., developers have to share their instruments. Users can then test and provide feedback. Some of these versions work, some do not. Some are better than others, which is why it's important to be part of a community where everyone shares their comments.