Firefox for Android has a number of tools that can be used to help debug web issues on Android devices. These include the Responsive Design Mode, which allows you to simulate different device sizes and resolutions, the Network Monitor for tracking requests and responses, and the JavaScript Debugger for debugging code. Firefox also has a built-in Web Developer Toolbar that can be used to inspect HTML and CSS code. Additionally, the Firefox Developer Tools can be used to inspect the DOM and troubleshoot JavaScript issues.