Examine source code of SoftCards

{
  "manifest_version": 2,
  "name": "SoftCards",
  "version": "0.2.4",
  "description": "Learn flashcards quickly",
  "browser_specific_settings": {
    "gecko": {
      "id": "softcards@js.edu",
      "strict_min_version": "57.0"
    }
  },
  "icons": {
    "32": "icons/sc.png"
  },
  "browser_action": {
    "default_icon": "icons/sc.png",
    "default_title": "SoftCards",
    "default_popup": "popup.html"
  },
  "permissions": [
    "storage",
    "tabs",
    "unlimitedStorage",
    "clipboardRead"
  ]
}