Your approach to mobile user testing should be task based. First, identify the main tasks of your app. In the next step, you let your test participants perform the task(s). Observe how they behave, how long they need to complete the task and ask for their feedback. You can also A/B test here and analyze if there is a difference between different versions. By the way, these are the best tools to run mobile app A/B tests on. The advantage of session replay software like UXCam is that you don’t need to recruit participants, you can just observe the behavior of real users.