Accompanying blog post
Send push notifications from your website using pushover's php api. You need to signup in pushover's website to receive your api key, and create an application to receive your application's api token. You need to put these two keys in the sent_notification.php file. To receive the notifications you need to download the pushover app from your device's application store. There are apps for Android and iOS. These have a 5 day free trial, after which you will need to buy a licence if you want to continue getting notifications in your device.