You can test mobile apps using Appium. But setting up Appium in-house is not a viable solution as You will also need to buy test devices (phones and tablets). Nowadays most of the companies will test the apps in cloud. There are many cloud test providers - Browserstack, Saucelabs and AWS device farm. Main benefit of testing apps in cloud is that you do not need to buy and maintain any device. All these providers support wide variety of platforms and configurations. You can test iOS and Android apps on many platforms like iPhones, Samsung phones, tablets, iPads etc.