When selecting tools for mobile testing, there are several factors to consider, such as compatibility with the product's features and technologies, cost, ease of use, functionality, and scalability. Popular tools for mobile testing include Appium, Firebase Test Lab, Xcode, TestFlight, and BrowserStack. Appium is a cross-platform framework for automated testing of native, hybrid, and web apps; Firebase Test Lab is a cloud-based platform for testing Android apps on real devices and emulators; Xcode is a development environment for testing iOS apps on simulators and real devices; TestFlight is a service for distributing and testing iOS apps with beta testers; and BrowserStack is a cloud-based platform for testing web apps on real devices and browsers. Each of these tools should be compatible with your product's features and technologies, fit your budget, be easy to use, offer the functionality you need, and be able to handle your test volume.