BUTON

Let's say you are a manager and you are attending many meetings outside your office. When you need something from your assistants it is impolite to take your phone and make a call or send a message. So you have "buton". It is a smart phone app with simple buttons.
The buttons are fully configurable. You decide the icon and the label on the button as well as the message to be sent to your assistants. You send a secret key to the people who will be expecting messages from you. They register themselves as listeneres and enter the key you have sent to their apps and voila! they start receiving push notifications when you press your button.