Accessing courses on a mobile device is more limiting then accessing courses from a computer. Before you create courses for a mobile devices it is important to clearly understand these limitations.
The most important issue to understand is the learners experience.
Many web courses use big graphics that look great on a computer but take up so much of the mobile screen there is no room remaining for content.
Course creators also use a lot of "rich media". That is moving images that look great on a computer but are not supported on most mobile devices.
Mobile devices are typically used in a very distracted environment. Learners may be on a bus, on a train, at the store, eating lunch, or at work.
The mobile device screen is very small. This limits what the learner can see and can make it difficult to read a large amount of content, view graphics, or see moving graphics.