Visual usability : principles and practices for designing digital applications / Tania Schlatter and Deborah Levinson.

Enhanced descriptions from Syndetics:

Imagine how much easier creating web and mobile applications would be if you had a practical and concise, hands-on guide to visual design. Visual Usability gets into the nitty-gritty of applying visual design principles to complex application design.You'll learn how to avoid common mistakes, make informed decisions about application design, and elevate the ordinary. We'll review three key principles that affect application design - consistency, hierarchy, and personality - and illustrate how to apply tools like typography, color, and layout to digital application design. Whether you're a UI professional looking to fine-tune your skills, a developer who cares about making applications beautiful and usable, or someone entirely new to the design arena, Visual Usability is your one-stop, practical guide to visual design.