Here are some tools to help you use the Golden Ratio in your designs to create pieces that work proportionally...
GoldenRATIO is an app that provides an easy way to design websites, interfaces and layouts according to the Golden Ratio. Available in the Mac App Store for $2.99, the app features a built-in calculator with visual feedback.
It also has a 'favourites' feature that stores you screen position and settings for repetitive tasks, and a 'Click-thru' mode that means you can use it as an overlay in Photoshop and still work on the canvas.
This calculator from Pearsonified helps you to create the perfect typography for your website in line with Golden Ratio principles. Just enter a font size, content width, or both into the field on the website, and click the Set my type! button. If you'd like to optimise for characters per line, you can enter an optional CPL value.
This simple but useful free app is available for both Mac and PC. Give it any number and it will calculate the corresponding number according to the golden ratio.
This on-screen ruler and grid software saves you all that messing about with calculations and allows you to design using the golden section proportion visually.
You can see and change the harmonious forms and sizes, while being directly in the process of working on your project. A regular license costs $49, but you can download a free trial version that's good for 30 days.
Golden Ratio tutorials
Finally, here are some handy tutorials to help you use the Golden Ratio in your designs to create pieces that work proportionally...
In this tutorial for Digital Arts, Roberto Marras shows how to use the golden section in your artwork, to create pieces that work proportionally.
02. Web design
This tutorial from Tuts+ explains how to apply the principles of the Golden Ratio to your web design projects.
03. More web design
This Smashing Magazine tutorial explains divine proportion and the Rule of Thirds and describes how you can apply both of them effectively to your web layouts. Some good starting points you can build upon or develop further.