Examine source code of Sketchit 2.0

{
  "background": {
    "scripts": [
      "sketch.js",
      "floodfill.min.js"
    ]
  },
  "browser_action": {
    "default_popup": "popup.html",
    "default_title": "Sketchit 2.0"
  },
  "description": "Create and save drawings on your browser.",
  "icons": {
    "16": "icons/icon16.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "manifest_version": 2,
  "name": "Sketchit 2.0",
  "version": "2.0",
  "browser_specific_settings": {
    "gecko": {
      "id": "{cd777e96-217e-42a6-961d-9b57133bf800}"
    }
  }
}