New icon wanted for photo editing iPhone app

Voxeloid

Our company creates and sells iOS apps on the AppStore.

I need a new icon for an iPhone app called Effect Touch. The app was very successfull at its release but sales declined since then. To give it a push as part of the next update I intend to replace the old, poor-looking icon with a better one.

The application lets the users apply different effects to part of a photo by "painting" the effect with their fingers.

A free to try lite version's itunes link: (viewable in a web browser) http://itunes.apple.com/us/app/effe…98730?mt=8
The second screenshot demonstrates how the "brush" strokes look like.

I am looking for an attractive icon that communicates this functionality well. One idea might be a brush/finger swiping through a photo/canvas leaving behind an effected/altered version of the image. I am open to other, perhaps simpler interpretations as well.

As there is a lite and a full version, the icon must remain recognizable with a "lite" banner placed at the bottom or in one of the corners. An optional advantage is if a small modification can easily be applied in order to create a differentiated version for an iPad port. (for example a background color can be changed easily)

The icon must look good and be comprehensible at the standard iPhone icon resolutions: 57x57 pixels for iPhones, 114x114 for iPhone 4, and 72x72 pixels for iPad. The artwork must also be available at 512x512 as required by the rules of the AppStore to display a larger version in iTunes. By default the appstore applies a gloss effect on the icons but it can be disabled. If you intend to use it, make it part of the submission so that the final look can be evaluated. (but you have to deliver the icon without the gloss too, the way it will be uploaded)

UPDATE: Two things based on the first few submissions. The icon can not contain the Apple logo in any form. It's a trademark, and they don't approve any apps in the appstore with such an icon. If you need an apple for the icon, it must be a generic one. The other thing is that the app has a lot of different tools as opposed to having only a desaturation tool. Many apps in the appstore are copying the "Color Splash" app, which only allows you to turn parts of the photo into grayscale. This app does a lot more, so I want to avoid looking like yet another copy of the above mentioned app, so please do not base your icon solely on this selective desaturation effect.