Catapush ensures additional level of deliverability of your mission critical messages by providing another mobile communication channel as backup option: the SMS which can sent when smartphones lose data connectivity (elevator, subway, train, etc.).
Catapush is the only push solution provider which enables to automatically resend the message as an SMS to all users who didn’t receive the push notification within a predefined timeframe after the push message expiry.
Check the API documentation for a list of all the available features and sample codes.