Examine source code of Super Water Reminder

{
  "manifest_version": 2,
  "name": "Super Water Reminder",
  "version": "1.2",
  "description": "A simple Super Water Reminder extension to get daily reminder about drinking water during work.",
  "icons": {
    "48": "icons/icon.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "henryusuao@gmail.com"
    }
  },
  "browser_action": {
    "default_icon": {
      "48": "icons/icon.png"
    },
    "default_popup": "popup.html"
  },
  "permissions": [
    "storage"
  ]
}