Examine source code of SnapSite

{
  "manifest_version": 2,
  "name": "__MSG_app_name__",
  "description": "__MSG_app_description__",
  "version": "0.0.4resigned1",
  "default_locale": "en",
  "icons": {
    "16": "assets/logo.png",
    "48": "assets/logo.png",
    "128": "assets/logo.png"
  },
  "background": {
    "scripts": [
      "app.js"
    ]
  },
  "browser_action": {
    "default_icon": "assets/icon.png",
    "default_title": "__MSG_app_actions_clipboard__",
    "default_popup": "actions/clipboard.html"
  },
  "permissions": [
    "<all_urls>"
  ],
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "handler.js"
      ],
      "run_at": "document_end"
    }
  ],
  "applications": {
    "gecko": {
      "id": "snapsiteapp@gmail.com",
      "strict_min_version": "47.0"
    }
  }
}