Photo Art - Color Effects is a photo-editing app that lets you apply a black and white effect over part of your picture.
Photo Art - Color Effects works in a pretty simple way: first you apply a black and white filter on the pic you want to edit, then you can draw and paint on it using your fingertip. There are three basic tools you can use: the brush, the eraser, and the zoom.
In the settings, you can customize your brush, changing its size, intensity, and pattern. The brush lets you apply colors where you use it. The eraser lets you undo this effect, giving the image its black and white filter back.
Photo Art - Color Effects is a pretty powerful photo-editing app that definitely provides good results. An excellent alternative for creating properly elegant pictures.