notify_by Pushover do |pushover|
  pushover.on_success = true
  pushover.on_warning = true
  pushover.on_failure = true

  pushover.user = 'USER_KEY' # required
  pushover.token = 'API_KEY' # required
  pushover.title = 'The message title' # optional
  pushover.device = 'The device identifier' # optional
  pushover.priority = '1' # optional

Pushover is a platform for sending and receiving push notifications to Android and iOS devices. Authentication requires the supply of two keys; an Application (API) token and a user token. Every connected device will require a device name which can then be used for targeting push notifications.

Messages sent through this notifier are restricted to 512 characters including the supplied title. Applications can send a maximum of 7,500 messages per month per application (API) key.

Please read the Pushover API documentation for further details of the configuration parameters. Registration is free, but you do need to purchase the device clients.