I've looked at TrueHDR in the past and found it a competent app for getting good photos in challenging exposure situations. HDR techniques are excellent when you are faced with taking photos of people when there is a bright sky behind them.
The app has been updated today with some worthwhile features and a sale price of US $0.99 for a limited time. New features include post-processing control of warmth, saturation and brightness, and there are now some effects like sepia, monochrome and vignetting.
I gave the app a quick test this morning and found the image quality quite good when there was both a bright sky and some deep shadows. I've included some screen shots in the gallery.
The app allows you to manually set exposure in different parts of the viewfinder or it can do it automatically. Images can be saved to your camera roll, emailed, or sent to Twitter or Facebook.
This is a nice update to an already good app. Processing and merging images into an HDR finished product takes under a minute, but it would be good if the app did the processing in the background. If you exit for a call or to check email, the rendering stops then resumes when it is active again.
If you are interested in better iPhone photos, TrueHDR is is a good way to start, and I think you will get better results than from the Apple built-in HDR feature.