It waits for new RAW images captured using a supported camera app, and then processes them in the background. It does this by using the power of your phone's graphics unit for up to a few seconds. The results have more details, higher dynamic range, and can improve over time when the application gets updated.

There are two reasons why using this app might be preferable over using Google Camera. The first reason is that the ports all have their own bugs and kinks, while the camera app included on the device usually works well in any situation, albeit with lesser quality. If something does go wrong in DNG Processor, the RAW file remains, so your shot is never lost. The second reason is that this app is fully open source and will get better over time through a community effort. People with image processing experience can take a look at the code and contribute, since there’s no obfuscation.

https://drive.google.com/open?id=1vCdjNCKu2GnEVwHnuQ3LkQkPnNZNQSj0