Examine source code of Select Tabs Extras

{
  "author": "igorlogius",
  "homepage_url": "https://github.com/igorlogius",
  "description": "Powerful tab selection addon with a bunch of one click options but also allow the user to create custom selection rules",
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_area": "navbar",
    "default_popup": "popup.html",
    "theme_icons": [
      {
        "light": "dark-256.png",
        "dark": "light-256.png",
        "size": 256
      }
    ]
  },
  "commands": {
    "All": {},
    "Invert": {},
    "Same Container": {},
    "Descendents": {},
    "Siblings": {},
    "Children": {},
    "Parent": {},
    "Ancestors": {},
    "Same URL": {},
    "Same Origin": {},
    "Same Domain": {},
    "Same Port": {},
    "Same Protocol": {},
    "To the Left": {},
    "To the Right": {},
    "Pinned": {},
    "Muted": {},
    "Loading": {},
    "Complete": {},
    "Audible": {},
    "Auto Discardable": {},
    "UserScripts": {}
  },
  "icons": {
    "512": "icon.png"
  },
  "manifest_version": 2,
  "name": "Select Tabs Extras",
  "options_ui": {
    "page": "options.html"
  },
  "permissions": [
    "storage",
    "tabs",
    "bookmarks",
    "menus",
    "notifications",
    "<all_urls>"
  ],
  "version": "1.2.2",
  "browser_specific_settings": {
    "gecko": {
      "id": "{26d546f0-e8cd-40e7-84b6-185a97cf651c}"
    }
  }
}