Examine source code of Subs Translate

{
  "manifest_version": 2,
  "name": "Subs Translate",
  "version": "1.2.4",
  "author": "cLe0",
  "icons": {
    "48": "images/st-icon.svg",
    "96": "images/st-icon.svg"
  },
  "applications": {
    "gecko": {
      "id": "substranslate@cLe0",
      "strict_min_version": "57.0"
    }
  },
  "browser_action": {
    "default_icon": "images/st-icon.svg",
    "default_title": "Subs Translate"
  },
  "background": {
    "scripts": [
      "st-options-helper.js",
      "st-background.js"
    ]
  },
  "options_ui": {
    "page": "st-options.html",
    "open_in_tab": false
  },
  "permissions": [
    "<all_urls>",
    "storage"
  ]
}