Great Interface

While the idea of creating a black and white photo with an accent of color has been done before, perhaps even overdone, Color Accent does it extremely well. The ability to select multiple accent colors, individually tweak the results, saturation, and hue shift of each, and finally manually edit the results with b&w, color, and accent brushes all combine in a very simple, straightforward interface. Ive tried several similar apps, kept two on my phone, and replaced them all with this.

Granular about Color Accent