Examine source code of Sound Control

{
  "version": "1.2.1resigned1",
  "name": "Sound Control",
  "description": "Manage audible web pages from a central location.",
  "homepage_url": "https://github.com/kumar303/sound-control/",
  "author": "Kumar McMillan",
  "browser_action": {
    "browser_style": false,
    "default_icon": {
      "48": "images/Boombox_48.png",
      "96": "images/Boombox_96.png"
    },
    "default_title": "Sound Control",
    "default_popup": "popup.html"
  },
  "commands": {
    "_execute_browser_action": {
      "suggested_key": {
        "default": "Ctrl+Shift+K"
      },
      "description": "Kick open the sound control panel"
    }
  },
  "background": {
    "scripts": [
      "dist/background.js"
    ]
  },
  "permissions": [
    "activeTab",
    "tabs"
  ],
  "manifest_version": 2,
  "browser_specific_settings": {
    "gecko": {
      "id": "{67b2c222-9d4e-4747-ad68-39e8ba76ca3b}"
    }
  }
}