I was tasked with rebranding Intuits W4 tax calculator using the new style guides that had just been released. It was designed to be fully responsive - all the way down to mobile, which was a real challenge. Prior to the rebuild the application required the download of a mobile app in order to use the calculator on a phone.
The new calculator is online and ready for use! https://turbotax.intuit.com/tax-tools/calculators/w4/