The Phaser Debug Tool is a Chrome and Firefox browser extension that, when invoked, checks for the existence of 'Phaser' within the page. If found, it hooks into it and provides all kinds of tools to inspect and modify the running game.
The following YouTube video shows a slightly older release, but you can still get a good feel for just how useful this extension is:
It has recently been updated and the developers continue to add new features. You can find the code in their GitHub repo. Features include:
- A real-time FPS meter.
- A list of all Scenes declared in the Scene Manager.
- A list of children active on the Display List, including the ability to edit their properties such as: name, visibility, alpha, position, rotation, scale and lots more.
- Support for extended Game Objects such as Spine and Text.
- View Containers, their stats and all of their children.
- Dynamically change Game Object textures or frames.
All of these changes happen dynamically, directly within the running game, making it a perfect extension to have installed during development and debugging.