Multi-touch gestures like swipe and pinch have introduced a new interaction paradigm that is currently used in developing mobile applications. Such applications can include different user gestures that cause different results for different interactions with the same user interface element. Testing such user interaction is complex. We present a formal task-based approach to automate testing of user gestures in mobile applications. In previous work, we used TaMoGolog, a formal task modelling language built on the top of the Golog family of high-level programming languages, for evaluating user interfaces along the development process. In this work, we present MobiGolog that extends TaMoGolog to support the testing of users' multi-touch gestures in the developing and developed mobile applications.