This app reminds me of basecamp. It has simple core functionality with an intuitive UI that really works well and it covers all of the basics you really need. It doesn't pack in a bunch of unused functionality that make it difficult to use, rather, it's sophistication comes from its simplicity. Email updates and integrated responses also work well. However, our favorite integration is with Skitch. Quickly skitching a picture and adding it as a viewable image to a ticket with some text description is powerful. A clear picture with a few notes and arrows is much easier than a detailed description.