Simply Color Effects HD is a straightforward image editing tool that allows you to swipe and paint with colors or black and white effects on any image you take. The process is easy and while the interface can be unnecessarily complex at times, there are enough options here to make it a useful standalone app for color changes.
When you open Simply Color Effects HD, you can choose to take a photo or load a photo. That photo is then converted to black and white and you can swipe your finger anywhere to paint in the original color from the image. You can change brush sizes and opacity or you can switch back and forth from black and white to color. The effect is that you have near limitless control over the color saturation of an image, item by item. While the screen is small and getting it pinpoint right will be tough, there are quite a few options here for tweaking and adjusting your images.
Simply Color Effects HD, as the name implies, does not offer editing options for other parts of your photos. It is strictly designed to change color effects and saturation on your photos. If you are looking for a more feature-rich app, there are some on the App Store that offer a combination of features. But if you don't mind using two apps on an image, combine Simply Color Effects HD with a good photo editor and you can do just about anything you want with your images.