Examine source code of Smart Texter

{
  "description": "New Style Quick Note , Easy Handling Text",
  "manifest_version": 2,
  "name": "Smart Texter",
  "permissions": [
    "find",
    "tabs",
    "activeTab",
    "<all_urls>",
    "storage",
    "clipboardRead",
    "clipboardWrite"
  ],
  "version": "1.2resigned1",
  "applications": {
    "gecko": {
      "strict_min_version": "57.0a1",
      "id": "{8ca35ccd-3938-47e3-8d58-84c35d880f33}"
    }
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "icons": {
    "32": "icons/writing32.png",
    "64": "icons/writing64.png"
  },
  "browser_action": {
    "browser_style": true,
    "default_title": "Smart Texter",
    "default_icon": {
      "32": "icons/writing32.png"
    }
  },
  "sidebar_action": {
    "default_icon": "icons/writing32.png",
    "default_title": "Smart Texter",
    "default_panel": "smartText.html"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "injection.js"
      ]
    }
  ],
  "commands": {
    "_execute_sidebar_action": {
      "suggested_key": {
        "default": "Ctrl+Shift+S"
      }
    }
  }
}