Examine source code of Yaklass_helper

{
  "manifest_version": 2,
  "name": "Yaklass_helper",
  "version": "1.2.1",
  "description": "yaklass helper by a3ldi",
  "icons": {
    "32": "icons/32.png",
    "64": "icons/64.png",
    "96": "icons/96.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "yaklass_helper_full@aeldi"
    }
  },
  "permissions": [
    "activeTab",
    "storage",
    "unlimitedStorage"
  ],
  "browser_action": {
    "default_icon": "icons/64.png",
    "default_title": "YaKlass Помощник",
    "default_popup": "index.html"
  }
}