People spend hours looking at their mobile phones and can use them to listen to podcasts while on the train or bus or in the car. You can access notes, slides etc too. Anything you can do online you can mostly do on a smart phone.

There is software specifically for developing eLearning and has settings that change the course to be more accessible on  mobile device. Adobe Captivate has "fluid boxes" that change size and shape based upon what device the content is being view in. Articulate 360 has a similar set of features. Both are effective, but there seems to be a consensus among Instructional Designers that Captivate is more responsive for m-learning content but harder to learn from a development perspective.

http://www.adobe.com/products/captivate.html

https://articulate.com/360

You may want to give a look at this link:

http://tracks.roojoom.com/r/82667

I'm offering mobile learning video lectures from various perspectives.

http://tracks.roojoom.com/r/82667

There's many definitions of Mobile Learning but the most recent and relevant is from (Helen Crompton, 2013) “learning across multiple contexts, through social and content interactions, using personal electronic devices” .

Of course the evolution of mobile technology have a direct impact on Mobile Learning, there's many kind of Mobile Learning:

• Mobile Learning (anywhere anytime learning, mobility)
• Mobile Social Learning(collaborative learning, Mobility+Social network)
• Pervasive Learning(Adaptive Learning, Mobility+Artificial Intelligence)
• Ubiquitous Learning(Context Aware Learning, Mobility+IoT and Smart Wearable Technology)