List of CIFilters available in iOS 5

CIAdditionCompositing,
CIAffineTransform,
CICheckerboardGenerator,
CIColorBlendMode,
CIColorBurnBlendMode,
CIColorControls,
CIColorCube,
CIColorDodgeBlendMode,
CIColorInvert,
CIColorMatrix,
CIColorMonochrome,
CIConstantColorGenerator,
CICrop,
CIDarkenBlendMode,
CIDifferenceBlendMode,
CIExclusionBlendMode,
CIExposureAdjust,
CIFalseColor,
CIGammaAdjust,
CIGaussianGradient,
CIHardLightBlendMode,
CIHighlightShadowAdjust,
CIHueAdjust,
CIHueBlendMode,
CILightenBlendMode,
CILinearGradient,
CILuminosityBlendMode,
CIMaximumCompositing,
CIMinimumCompositing,
CIMultiplyBlendMode,
CIMultiplyCompositing,
CIOverlayBlendMode,
CIRadialGradient,
CISaturationBlendMode,
CIScreenBlendMode,
CISepiaTone,
CISoftLightBlendMode,
CISourceAtopCompositing,
CISourceInCompositing,
CISourceOutCompositing,
CISourceOverCompositing,
CIStraightenFilter,
CIStripesGenerator,
CITemperatureAndTint,
CIToneCurve,
CIVibrance,
CIVignette,
CIWhitePointAdjust