Examine source code of Pocket Synth

{
  "manifest_version": 2,
  "name": "Pocket Synth",
  "description": "A playable synthesizer in your toolbar: 2-octave keyboard, 4 waveforms, drum pads and a 16-step sequencer with saveable patterns.",
  "version": "2.1.0",
  "browser_specific_settings": {
    "gecko": {
      "id": "{94b60521-1a21-48e9-9000-a4d9b899769b}",
      "strict_min_version": "101.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "icons": {
    "32": "assets/icon-32.png",
    "48": "assets/icon-48.png",
    "64": "assets/icon-64.png",
    "96": "assets/icon-96.png",
    "128": "assets/icon-128.png"
  },
  "permissions": [
    "storage"
  ],
  "browser_action": {
    "default_title": "Pocket Synth",
    "default_popup": "src/popup.html",
    "default_icon": {
      "32": "assets/icon-32.png",
      "48": "assets/icon-48.png",
      "64": "assets/icon-64.png",
      "96": "assets/icon-96.png",
      "128": "assets/icon-128.png"
    }
  }
}