Examine source code of htmltoExcelSheet

{
  "description": "A add-on to convert html to excel file",
  "manifest_version": 2,
  "name": "htmltoexcel",
  "version": "2.1resigned1",
  "icons": {
    "48": "icons/downloadarrow.png"
  },
  "background": {
    "scripts": [
      "htmltoexcel.js"
    ]
  },
  "browser_action": {
    "default_icon": "icons/downloadarrow.png",
    "default_title": "Download Excel sheet!",
    "browser_style": true
  },
  "permissions": [
    "activeTab",
    "tabs",
    "downloads"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{6625e3a8-2cef-4d0f-8621-6ed1bf6e479c}"
    }
  }
}