IT Ops folks have been using electronic devices for notifications for decades. It started with pagers on our belts and pagers got more sophisticated in time.
Alpha numeric pagers followed numeric ones that could only display a phone number; and two way pagers with tiny keyboards followed them. Pagers still get used by some operations folks but largely have been replaced by mobile phones thanks to text messaging capabilities available on almost any mobile phone. IT operations processes largely use email as the main communications method to notify users when an action is required and rely on short text messages (SMS) when there is some urgency.