As you begin thinking about your elearning project, you'll want to consider mobile device usage as well. More and more elearning development tools are taking mobile devices into consideration. The good news is that the majority of the tools you'll encounter and likely use will publish to a format that can be opened on most mobile devices. But just because something will open on a mobile device, doesn't mean the learning experience will be great.
If the majority of your learners will be watching the elearning on a smartphone, consider publishing short, micro-lesson videos that are self-play, rather than a more traditional, slide-based interactive elearning course. If tablets are the device of choice among your learners, slide-based courses with interactivity can work, but you'll want to keep the requirements more simple. Some interactions offered by tools such as Captivate and Storyline don't always work on a tablet, or are difficult to accomplish (drag and drop is a good example).
Captivate and Mobile Design
For those interested in using Captivate, the newest version now includes a "responsive design" template. While not truly responsive design, in that it does not automatically adjust content to the learner's chosen device, it offers a three-size format for designing your training. You create your course in a standard laptop/desktop format, and can then switch to both a tablet and smartphone "view" from which you can pare down the content to better fit those screens, as shown below.
To get started with Captivate's responsive design features, see the "Responsive Elearning Basics" module from Captivate 8 Advanced Techniques on Lynda.com.