Examine source code of tooltipr

{
  "manifest_version": 2,
  "name": "tooltipr",
  "description": "Enhancing your browsing experience to learn every topic you ever wanted to learn about!",
  "version": "0.0.6",
  "icons": {
    "16": "16.png",
    "48": "48.png",
    "128": "128.png"
  },
  "browser_action": {
    "default_icon": "128.png",
    "default_popup": "popup.html"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "js/vendor.js",
        "js/content_script.js"
      ]
    }
  ],
  "background": {
    "scripts": [
      "js/vendor.js",
      "js/background.js"
    ],
    "persistent": false
  },
  "permissions": [
    "storage",
    "cookies",
    "<all_urls>"
  ],
  "applications": {
    "gecko": {
      "id": "tooltipr@gmail.com",
      "strict_min_version": "53.0"
    }
  }
}