Although Get Help is not a successful application and has many flaws, I believe the points my team and I learnt about User Interface and Interaction Design are worth sharing with others who are designing web apps. These are slides from a presentation we gave sharing the points we learnt.
Note: They may not be self-sufficient as there were lots of verbal explanations during the presentation. Here is a link to a detailed case study which was a handout to accompany the presentation. http://www.slideshare.net/suyuen/gethelp-ui-interface-and-interaction-design-case-study