Known issues
General issues
On some devices, exposure compensation changes viewfinder brightness but only affects captured photos if flash is on, and on some devices it does affect captured photos at all. This is a hardware/driver issue, which can also be reproduced with the built in camera application, and cannot be fixed in application level.
Device specific issues
Nokia 808 Pureview
On Nokia 808 autofocus completely locks exposure. This means that after focusing or locking focus, changing exposure compensation has no effect.
Nokia C5-00
At least on some software versions, exposure compensation setting has no effect. The same issue also affects the built-in camera application.
Nokia N73
Exposure compensation setting affects viewfinder, but not captured images.