This study analyses different techniques used for evaluation of various usability dimensions of software applications (apps) being used on the smartphones. The scope of this study is to evaluate various aspects of the usability techniques employed in the domain of smartphone apps. Usability assessment methodologies are evaluated for different types of applications running on different operating systems like Android, Blackberry and iOS, etc. Usability evaluation techniques and methodologies with respect to usability heuristics like field experiments, laboratory experiments models and usability standards are discussed in detail. The issues for evaluation of usability of smartphone apps are identified by considering limitations and areas of improvement outlined in the contemporary literature. A conceptual framework for usability evaluation of smartphone apps is also designed which would be validated through experimentation in the thesis work. This study is particularly useful to comprehend usability issues and their likely remedies to produce high quality smartphone apps.