The new camera2 API introduced in Android 5 Lollipop can bring controls typically found with in a DSLR camera to Android smartphone camera. You can manually control shutter speed, manual focus, ISO, white balance, camera exposure, etc. It means you can adjust your shooting parameters to take better photos. However, it requires camera app that utilizes the new API, like the AZ Camera.
AZ Camera app, which is a free download on Play store, has better utilizes the full advantages of Android 5 Camera2 API. Besides the usual camera features, this camera app supports raw format (DNG) and allows you to manually adjust camera shutter speed, focus, ISO, white balance and camera exposure, like in a professional DSLR camera.
Though AZ Camera app can utilize advantages of Android 5’s camera2 API, your phone manufacturer must implement the API to the phone. Currently it only works correctly with Google Nexus 5 and Nexus 6 smartphones.
The cameras on smartphones are consistently getting better. We are seeing more megapixels than ever before and some manufacturers are even including sensors typically found within DSLR cameras into them as well. However, to make best out of it requires a good camera app like the AZ Camera and phones that supports new Camera2 API.