Testing mobile applications with complex UI components can be challenging, but Appium provides several ways to handle them. One approach is to use the Page Object Model (POM) design pattern, which helps in organizing and managing the test scripts. With POM, UI components are represented as page objects, and each page object is associated with a set of related tests. This approach makes it easier to manage the complexity of the UI components and makes the test scripts more modular and maintainable.

Another approach is to use XPath or CSS selectors to locate and interact with the UI components. Appium provides several methods to locate elements using these locators, including findElementByXPath, findElementByCssSelector, and findElementsByXPath. These methods can be used to interact with UI components, such as buttons, input fields, and dropdown menus.

Appium also provides a range of gesture and action APIs that can be used to interact with complex UI components. For example, the TouchAction class can be used to perform complex gestures, such as swiping, dragging, and pinching. The Actions class can be used to perform actions such as clicking, double-clicking, and right-clicking.