From Atrise Software:
Golden Section is an adjustable transparent design grid for web, graphic, logo and UI designs. It allows you to control and correct the sizes and proportions in your design project using the golden section ratio. From the earliest times, human cultures have striven to define beauty. A study of nature, architecture, and art reveals that a common principle - that of pleasant proportion - is a universal characteristic that contributes to defining beauty. The proportion that is pleasing to the eye is the Golden Section, or simply the ratio of one relationship to another, or 1 to 0.618. Now you can use this same ratio in your design projects. Atrise Golden Section allows you to quickly and easily check the sizes and proportions in your on-screen design projects by using the ratio of the Golden Section. It generates a resizable grid that overlays your work and displays the Golden Section ratio. Beauty and proportion can now be discovered as easily as moving your mouse. Once activated, the program creates a resizable grid overlay that "floats" over your project.