The demand for education has continued to increase, unabated. Consequently there is a corresponding need to identify and design more affordable ways or models for increasing access to learning opportunities. Coincidentally, similarly being witnessed is an unprecedented explosion in mobile devices being produced, particularly mobile phones. The technology which is arguably the commonest means of communication, could help in extending the possibilities for teaching, learning and research in formal and informal settings. This paper reviews mLearning models and evaluates theirs strengths and weakness.