Mobile app testing has plenty of challenges based on multiple factors: nature/type of the app (native, mobile web, hybrid), the platform the app is supposed to run on, mobile specific testing constraints (interruptions in active mode, memory limit, battery state, different network conditions, sim card, etc).
Due to the huge variety of devices and OSs in the market there is a critical demand to test the app against at least most popular devices based on app's target market regional statistics. This brings a lot of obstacles in terms of availability of those devices that are a must to be covered to make decent compatibility testing. Does ‘testing without real mobile device onside’ rectify this obstacle?
Based on nature of the app under test several techniques/technologies come in handy for mobile app test automation which brings variety of challenges depending on technologies used.