Examine source code of BrainTool

{
  "manifest_version": 2,
  "name": "BrainTool",
  "description": "BrainTool - Go Beyond Bookmarks",
  "default_locale": "en",
  "version": "1.3.1",
  "permissions": [
    "tabs",
    "storage",
    "webNavigation",
    "bookmarks",
    "https://BrainTool.org/versions/*"
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "content_scripts": [
    {
      "matches": [
        "https://BrainTool.org/versions/*"
      ],
      "run_at": "document_idle",
      "js": [
        "btContentScript.js"
      ]
    }
  ],
  "browser_action": {
    "default_icon": {
      "16": "images/BrainTool16.png",
      "32": "images/BrainTool32.png",
      "48": "images/BrainTool48.png",
      "128": "images/BrainTool128.png"
    },
    "default_title": "BrainTool!",
    "default_popup": "popup.html"
  },
  "icons": {
    "16": "images/BrainTool16.png",
    "32": "images/BrainTool32.png",
    "48": "images/BrainTool48.png",
    "128": "images/BrainTool128.png"
  },
  "commands": {
    "_execute_browser_action": {
      "suggested_key": {
        "default": "Alt+B"
      }
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{11ec8c35-6d87-4a29-9483-62b8888a82f6}"
    }
  }
}