Graphic design is the part of app design everyone is familiar with—the area in which the pixels, colors, animation, and visuals of the app appear. This is where your wireframes become mockups. Before you start on your graphic design, you need to have in mind what you want your graphic design to be like.
What feeling do you want to give your target market? (Do you want them to feel entertained, focused, hardworking, etc.?)
What colors do you have in mind, if any?
What are some other apps you want ...