Examine source code of Simple Bookmarks Tree

{
  "manifest_version": 2,
  "name": "Simple Bookmarks Tree",
  "version": "1.2resigned1",
  "description": "Simple Bookmarks Tree",
  "icons": {
    "16": "img/icon16.png",
    "32": "img/icon32.png",
    "48": "img/icon48.png",
    "128": "img/icon128.png"
  },
  "browser_action": {
    "default_icon": "img/icon19.png",
    "default_title": "Simple Bookmarks Tree",
    "default_popup": "bpopup.html"
  },
  "web_accessible_resources": [
    "img/icon19on.png",
    "img/icon19off.png"
  ],
  "applications": {
    "gecko": {
      "id": "Simple_Bookmarks_Tree_senna5150ando@gmail.com",
      "strict_min_version": "57.0"
    }
  },
  "options_ui": {
    "open_in_tab": true,
    "page": "options.html"
  },
  "permissions": [
    "bookmarks",
    "sessions",
    "<all_urls>",
    "tabs"
  ]
}