Mobile applications and specifically their UI exhibit a set of features that make their design, implementation and testing particularly challenging: the variety of devices with their different characteristics and the quick pace of evolution. As with other types of E2E testing, the fragility of test cases represents an important hurdle to a wider adoption. This lecture will analyze the mobile-specific features of E2E testing; it will provide an overview of the testing technology approaches and the main tools available. A focus on the main causes of test fragility will provide an overview of the main pitfalls and provide a set of guidelines to avoid them. Finally we will focus on the prospective techniques to combine different approach to achieve higher test resilience and reusability. The lecture will provide evidence gathered from large empirical studies of OSS as well as experiment conducted on specific use cases.