Im usually very happy with the automatic effect. The results can look a little surreal at times, but much better than most tone-mapping, artificial HDR effects. And always better than the non-corrected image. In fact, Ive found that tone mapping is very hard to apply manually without looking cartoonish or blowing out areas of the photo. The devs have found a way of applying a subtle tone map effect across a broad range of imaging conditions, automatically. Of course, the ability to adjust settings and compare with the automatic (and original) photos only makes this app better. Some other enhancements apps (Camera+ Clarity) do a good job too, but often have very limited options for adjusting the effect.