Examine source code of Make My Day by Toggl

{
  "update_url": "https://clients2.google.com/service/update2/crx",
  "name": "Make My Day by Toggl",
  "short_name": "Make My Day",
  "version": "1.0.5",
  "manifest_version": 2,
  "description": "Auto generated time entries for your workday inside of the Toggl webapp",
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "https://toggl.com/*",
        "https://www.toggl.com/*",
        "http://local.toggl.space:9001/*",
        "*://*.toggl.space/*"
      ],
      "js": [
        "content.js"
      ]
    }
  ],
  "browser_action": {
    "default_icon": {
      "16": "images/icon-16.png",
      "32": "images/icon-32.png",
      "128": "images/icon-128.png"
    },
    "default_popup": "html/popup.html",
    "default_title": "Make My Day"
  },
  "icons": {
    "16": "images/icon-16.png",
    "32": "images/icon-32.png",
    "128": "images/icon-128.png"
  },
  "permissions": [
    "webNavigation",
    "tabs",
    "storage",
    "*://*.toggl.com/*",
    "*://toggl.com/*",
    "*://*.toggl.space/*",
    "*://beta.toggl.space/*",
    "*://toggl.space/*"
  ]
}