Mobile devices, in Rosen's discussion, include both smartphones and tablets. Although technically speaking they are computers, tablets such as the iPad, the various Android devices, and Kindle Fire are more like big smart phones. That is to say, tablets use the operating systems and browsers found on smart phones and share many limitations, such as low processor power and memory.

There are two methodologies that designers and developers can deploy to create content for mobile devices - to create mobile apps or to create Web apps - and Rosen points out the fundamental difference between them. Mobile apps are software programs specifically designed and developed for each unique mobile platform. In contrast, Web apps are Web sites specifically designed to work on all, or nearly all, mobile devices.

Developing mobile apps for mobile devices is similar to the way software was developed for computers back in the 1980s in that each platform is a world unto itself. If you develop an app that runs on iPhones and iPads, you will need to redesign it and use completely different development processes for the Android, Blackberry, and Microsoft platforms because each platform has a unique design, architecture, and programming requirements.

On the other hand, if you develop Web apps, all devices can (theoretically) access the same content and courseware. With just this bit of knowledge, one would think that the better choice is to develop Web apps and not bother with mobile apps. Unfortunately, the limitations of Web apps make this decision more complicated than it appears at first glance.