Prior to the iPhone camera software being updated by Apple to take HDR photos, I played with a couple different options. Of those, I used Pro HDR more often than not when I had time for a high quality image. I say “when I had time” because it used to take a lot longer to take a HDR image than a simple photo.
Even thought HDR is built into the iPhone OS, it doesn’t delivery the level of photos as the specialty apps. Pro HDR used to take a bunch of steps to take an image, keep the iPhone still and after the program got done crunching the first photo you would take the second. Then, a full minute later the app had merged the two photos to give you a very nice image.
The newest version of Pro HDR is much faster, can be used in fully automatic mode, has the option to take a even faster ‘low’ resolution image, and can take images using either of the two cameras. The HDR feature built in only works on the outward facing camera.
While I don’t use it a lot, the final image is presented on a screen with many fine tuning sliders. When I do use the feature, it has saved me from having to take the images again by lightening or enhancing.