If you're looking for a camera app that gives you advanced controls over how your pictures look, you might want to give Obscura a try. While offering advanced functionality made possible by iOS 8, Obscura is straightforward and simple to use. Big, clearly-labeled buttons let you control focus, exposure, and more. You can set the focus area by tapping anywhere on your phone's display.
Here are some of the powerful features you can look forward to in Obscura Camera:
Quick Focus lock
Quick Exposure lock
Manual ISO controls
Manual Shutter Speed controls
Manual Flash controls
3 Grid overlays (Rule of Thirds, Square and Circle)
9 Filters included (6 more available via In-App-Purchase)
Every control is easily reachable with one thumb
Obscura Camera is available right now as a free download on the App Store.