Examine source code of Cache Clearer

{
  "manifest_version": 2,
  "name": "Cache Clearer",
  "version": "1.1",
  "description": "Clears Firefox cache every 30 minutes",
  "permissions": [
    "browsingData",
    "alarms"
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": true
  },
  "icons": {
    "48": "icon.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{7ef89d79-1eb0-4f25-94c2-42895a6279b7}"
    }
  }
}