Does your app run smoothly on devices with numerous combinations of OS and devices? Testing is most important! But, Lab test alone will never guarantee that it will! You’ll need representative devices in terms of screen sizes, memory, etc., test the app on them, and optimize it accordingly. Unfortunately, most companies don’t do this because of lack of devices. But, now, it is possible to ensure your app is stable and performs smoothly on all devices when it is launched in the real world.