Examine source code of Noteblock

{
  "manifest_version": 2,
  "name": "Noteblock",
  "version": "1.3.2",
  "description": "Simple text editor",
  "icons": {
    "16": "icons/icon16.png",
    "24": "icons/icon24.png",
    "32": "icons/icon32.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "browser_action": {
    "default_icon": "icons/icon128.png",
    "default_popup": "editor.html",
    "default_title": "Noteblock"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "noteblock@bluebanana.hr",
      "strict_min_version": "42.0"
    }
  }
}