Add the Apple Push Notification Service (APNs) at your site.
This plugin implements the Apple Push Notification Service (APNs) and allows you to send notifications from your site to all devices that have installed your app. A button is added next to the button for publishing the post on the edit page to do this.
All registration/deletion requests must be sent to a specific URL of the website and must be composed by the UDID code followed by the device token (Look at the documentation page of plugin after installation).
In the settings page you can also upload your PEM certificate file and set all other information such as PEM SSL password, SSL server url and port. The PEM file will be stored in a protected folder for security reason.