Examine source code of Google Keep V2

{
  "manifest_version": 2,
  "name": "Google Keep V2",
  "version": "1.3",
  "description": "Access Google Keep quickly via Firefox toolbar popup and sidebar, plus save selected text or page quickly.",
  "icons": {
    "32": "icons/logo_32.png",
    "64": "icons/logo_64.png",
    "128": "icons/logo_128.png"
  },
  "permissions": [
    "sidebar_action",
    "contextMenus",
    "tabs"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_title": "Google Keep",
    "default_popup": "popup.html",
    "default_icon": {
      "32": "icons/logo_32.png",
      "64": "icons/logo_64.png",
      "128": "icons/logo_128.png"
    }
  },
  "sidebar_action": {
    "default_panel": "sidebar.html",
    "default_icon": {
      "32": "icons/logo_32.png",
      "64": "icons/logo_64.png",
      "128": "icons/logo_128.png"
    },
    "default_title": "Google Keep Sidebar"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{d914200e-6258-48b4-a8ae-92216c0b99d7}"
    }
  }
}