Camera+ is feature rich, and as a free lite version of Camera+Pro, it is a powerful, feature rich package that can replace the native camera and most post processing apps. In fact, its slight shutter speed lag and its understandable lack of HDR functionality are the only reasons I went back to the native iPhone camera.
(edit, Nov 21, thanks to Jimmy) Tap Tap Tap is the developer, and as of now this fantastic app is no longer in the App Store. I have no issues with the quality of this app, and they issue updates often enough to keep it clean and bug free for the most part. Why did Apple pull it? Because it provides for the use of the volume button to activate the "shutter", a clear violation of terms for developers. No using hardware buttons! Oddly, I have never used this feature, so habitualized am I to using the screen button.
If I had one space on my iPhone for an imaging app, this would be the one.
I first read about Camera+ on Lisa Bettany's blog, via a link from I forget where. But it what intrigued me was that Tap Tap Tap was using a professional photographer to create the easy to use workflow and photo treatments.
One of the best things about Camera+ is that all the photos you take with it are saved to a "lightbox", where you can decide what to do with them before saving to your Camera Roll. At first I thought this was a hokey way to make you think you were a big time Life photographer (a good angle in Heller's Catch 22), but I came to appreciate that it was cleaner and forced me to deal with photos rather than accumulating them for work "later".
This photo, of a cafe in Manhattan was treated with "Magic Hour", to make it warmer and more inviting than the native light.
And inside the cafe I used So Emo just because it can be fun to do so. This is a whimsical look that can make straightforward portrayals more dramatic and evocative.
This old modem in our local airport was treated with Hipster, kinda period appropriate I thought.
This salad was post processed using the Food filter, which increased the sharpness and contrast, and warmed it up a touch. It is really sensational when used on french fries.
In all, there are 27 of these FX treatments, including one called HDR, which is fun, but should not be confused with the serious HDR function of the iPhone's native software, nor apps like TrueHDR.
Additionally, Camera+ has cropping and 11 "scenes" that you would find on any point n shoot camera, like Flash for increasing shadow exposure, Backlight, Scenery, Text and Food.
In all, Camera+ is the imaging app I find most essential to my iPhotog style. Thank you Tap Tap Tap and Lisa Bettany! How lucky we are to enjoy such good work at such little cost!