Appium is a powerful tool for automated functional testing of mobile apps. Using Appium with Python and the Nose testing framework allows developers to write tests in their preferred language. The process involves installing Appium's dependencies, setting up the sample app, and running the tests using the `nosetests` command. The example test provided demonstrates how to launch an iOS app, fill out forms, click buttons, and verify expected results. The test uses Python classes and methods to interact with the app, including a `setUp` method to initialize the test environment, a `tearDown` method to clean up after each test, and a helper method `_populate` to fill in form fields.