The goal of the app is to provide a step-by-step tutorial on how to change a tire, which can be used on the spot when someone needs it most -- you've got a flat tire!

Rather than inventing our own content from scratch, we will start with the wikiHow article, How to Change a Tire, which can be found at http://www.wikihow.com/Change-a-Tire (under Creative Commons license). We are using it to illustrate how one might use Augmented Reality for How-to type instruction manuals. A screen capture of the wikiHow article page is shown ahead:

To be honest, it was pure luck and fortuitous that we found this wikiHow article with annotated images and videos. When we first decided on this subject for the chapter, we assumed we would write all the instructions ourselves. Then we discovered the wikiHow article. Even better, the images and videos have been marked up, which fits very well and is in line with the objectives of our project -- demonstrating the value of annotating real-world imagery. Moving this concept to live AR helps make the point that this is a natural next step for content presentation.

The content will be imported into the project from a Google spreadsheet. This, too, is a realistic scenario where one person or team may be developing and maintaining the application code, while others may be responsible for writing and editing the content.