Examine source code of FB2 Reader

{
  "manifest_version": 2,
  "name": "FB2 Reader",
  "version": "2.5",
  "description": "Offline FB2 book reader with personal library, reading progress and customizable themes",
  "browser_specific_settings": {
    "gecko": {
      "id": "fb2reader@extension",
      "data_collection_permissions": {
        "required": [
          "none"
        ],
        "personally_identifying_info": false,
        "technical_and_interaction_data": false
      }
    }
  },
  "icons": {
    "48": "favicon.png",
    "128": "icon-128.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_title": "FB2 Reader",
    "default_icon": {
      "48": "favicon.png",
      "128": "icon-128.png"
    }
  },
  "permissions": []
}