Examine source code of Save Tabs

{
  "name": "Save tabs",
  "version": "1.0.0",
  "description": "Save opened urls for every open tab and every opened window",
  "manifest_version": 2,
  "permissions": [
    "tabs",
    "downloads"
  ],
  "options_ui": {
    "page": "view/options/options.html",
    "open_in_tab": true
  },
  "icons": {
    "16": "icons/icon16.png",
    "32": "icons/icon32.png",
    "64": "icons/icon64.png",
    "96": "icons/icon96.png",
    "128": "icons/icon128.png"
  },
  "background": {
    "scripts": [
      "background_scripts/background.js"
    ],
    "persistent": false
  },
  "browser_action": {
    "default_title": "Save tabs",
    "default_popup": "popup/popup.html"
  }
}