Examine source code of IceShot

{
  "manifest_version": 2,
  "name": "IceShot",
  "version": "1.1",
  "description": "Capture full-page or visible area screenshots in one click.",
  "icons": {
    "16": "icons/icon.png",
    "48": "icons/icon.png",
    "128": "icons/icon.png"
  },
  "permissions": [
    "activeTab",
    "tabs",
    "storage",
    "<all_urls>"
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "browser_action": {
    "default_icon": {
      "16": "icons/icon.png",
      "48": "icons/icon.png",
      "128": "icons/icon.png"
    },
    "default_title": "IceShot",
    "default_popup": "popup.html"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content_script.js"
      ]
    }
  ],
  "web_accessible_resources": [
    "copypage.html",
    "visible.html"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{d51d8a45-4c09-4bf1-b8a1-881c0c291f47}"
    }
  }
}