Examine source code of Scrollmark

{
  "manifest_version": 2,
  "name": "scrollmark",
  "description": "Save your last scroll position",
  "version": "0.0.2",
  "icons": {
    "24": "icons/icon.svg",
    "48": "icons/icon.svg",
    "64": "icons/icon.svg",
    "96": "icons/icon.svg",
    "128": "icons/icon.svg"
  },
  "permissions": [
    "activeTab",
    "storage"
  ],
  "content_scripts": [
    {
      "matches": [
        "*://*/*"
      ]
    }
  ],
  "browser_action": {
    "default_icon": {
      "24": "icons/icon.svg",
      "48": "icons/icon.svg",
      "64": "icons/icon.svg",
      "96": "icons/icon.svg",
      "128": "icons/icon.svg"
    },
    "default_popup": "browserAction/index.html",
    "default_title": "scrollmark"
  }
}