I'm looking for an iPhone app that features exposure compensation, any suggestions?
Camera+ claims to let you adjust the exposure (which is what exposure compensation does)!
Technically the answer is "there isn't one." The SDK does not allow much control over the camera so any apps claiming to do exposure compensation are just "faking it" by post-processing the image.
With the built-in photo app, you can adjust the exposure by pointing at the part of the scene that it should take the exposure from (it also focuses on the same point). This works on the 3GS and above. This trick should work in any app that can take pictures, too.
Currently, the default iOS Camera app that comes with all iPhones does exposure compensation. All you do is tap to set focus/metering, and a little sun icon comes up. Dragging up/down lets you increase/decrease exposure.
I know this is no quite about EC, but I thought this might be useful...
I don't have an iPhone myself (more of an Android person...), but I have a friend with an iPhone and he has the Pro HDR app. I must say I was quite impressed when I saw it work; you just click two positions on the preview of the image and it takes two photos, one after the other and then aligns and merges them. I wish someone would create such an app for Android :-)
It costs, ($1.99) so I would say that it's probably only worth it if you have a 3GS, because the cameras on the 3G and below are notoriously bad. And the iPhone 4 has HDR built in!
For some examples look here: http://www.flickr.com/groups/prohdr/
I've used Camera+; Touch Exposure & Focus feature
Set exposure separately from focus for the ultimate control of your shots… simply touch with a 2nd finger while focusing to adjust exposure until your shot is perfect. iPhone 4 and 3GS running iOS 4 only
It works as explained, but it's almost impossible to hold the phone, touch two spots on the screen and then touch the shutter icon. It's much more trouble than it's worth.
I think the original Camera+ used the volume buttons as a shutter, and was pulled from the app store for failure to follow Apple guidelines.
KitCamera seems to be able to do what you're asking for. It's now free, and has an actual exposure compensation slider. Which is a bit odd, as that's not supposed to be possible. Perhaps it's a hack or a kludge; I don't know. Regardless, iOS 8 allows apps to do this natively, so we'll likely be seeing this feature added to many camera apps.
The iPhone camera doesnt suck, it's more often the operator who has not taken the time to learn how to use it correctly. I've got many images that are as good or better than my D700. They were often times simpler to get and didnt require me to carry 8Lbs of camera around. I did a show where I mixed iPhone 4S and 5S images with DSLR images and challenged anyone in the audience to tell which was which. Nobody could. The whole "the Iphone (or any other smartphone) is a not a real camera" thing is an urban myth.
When i use my Procam6 app, if i want to compensate ( change the exposure from what the app wants to set ) i just tap on shutter speed ( or ISO ) and change it the amount of stops i feel is necessary.
"Note: While in auto mode, the exposure (AE) value can be set between -8 and 8+. The camera will automatically and continuously adjusts ISO and shutter speed to achieve the selected exposure value. The default value is 0, which means that no changed were made to ISO or shutter speed."