Examine source code of Epoch Converter

{
  "manifest_version": 2,
  "name": "epochconverter",
  "version": "2.0.2resigned1",
  "description": "Convert epoch datetime to normal date format and vice versa",
  "homepage_url": "https://github.com/cubble",
  "icons": {
    "48": "icons/icon-60.png"
  },
  "browser_action": {
    "default_icon": "icons/icon-32.png",
    "default_title": "Epoch Converter",
    "default_popup": "popup/popup.html",
    "browser_style": false
  },
  "applications": {
    "gecko": {
      "id": "{f5165b45-ad12-4847-90f3-d4dea3201fc4}"
    }
  },
  "options_ui": {
    "page": "settings/options.html"
  },
  "permissions": [
    "storage"
  ]
}