Examine source code of Gyazo

{
  "description": "__MSG_extensionDescription__",
  "author": "Helpfeel Inc.",
  "permissions": [
    "<all_urls>",
    "activeTab",
    "contextMenus",
    "storage"
  ],
  "optional_permissions": [
    "clipboardWrite"
  ],
  "background": {
    "scripts": [
      "main.js"
    ],
    "persistent": false
  },
  "browser_action": {
    "default_icon": {
      "19": "icons/19.png",
      "38": "icons/19@2x.png"
    }
  },
  "web_accessible_resources": [
    "imgs/crop.svg",
    "imgs/cross.svg",
    "imgs/grid.svg",
    "imgs/selection.svg",
    "imgs/spinner.svg",
    "imgs/window-scroll.svg",
    "imgs/window.svg",
    "menu.css"
  ],
  "icons": {
    "16": "icons/16.png",
    "19": "icons/19.png",
    "30": "icons/30.png",
    "32": "icons/16@2x.png",
    "38": "icons/19@2x.png",
    "44": "icons/44.png",
    "48": "icons/48.png",
    "50": "icons/50.png",
    "96": "icons/48@2x.png",
    "128": "icons/128.png",
    "150": "icons/150.png",
    "256": "icons/128@2x.png"
  },
  "options_ui": {
    "page": "option/options.html",
    "chrome_style": false
  },
  "manifest_version": 2,
  "default_locale": "en",
  "name": "__MSG_extensionName__",
  "short_name": "__MSG_extensionShortName__",
  "version": "4.2.0",
  "browser_specific_settings": {
    "gecko": {
      "id": "gyazo-extension@gyazo.com"
    }
  }
}