Testing and quality assurance are crucial for mobile app teams, as a significant number of users are likely to abandon apps due to bugs and glitches. Maximizing test coverage is essential for ensuring a quality user experience, but it presents challenges such as determining the extent of coverage without delaying releases. Test coverage measures how much of an app has been tested, including device and OS variety, and while perfect coverage is unattainable, aiming for around 70% is a practical target. This involves careful planning, prioritizing critical components, and balancing test and code coverage. Device and OS coverage require strategic planning to accommodate different behaviors and capabilities, using tools like emulators to streamline the process. Test automation aids in efficiently covering repetitive tasks but should complement rather than replace manual testing. Manual testing, including "in the wild" testing through alpha and beta releases, is vital for identifying real-world issues and maintaining high-quality app performance across various conditions.