In our home, it seems everyone in the house has either an iPhone, iPod Touch, or an iPad, and half of them constantly need help from me to use them. I'm looking for an iOS app with a companion Mac/web app that would allow me to push custom notifications out, either to specific devices or all devices on the network. The notifications would include a custom message and custom buttons with a specified calendar event, contact card, app, website, or settings pane associated with them. Example: If I'm aware of a change in our household calendar, our contact list, an update for iOS, or even an interesting news story, I could push out a notification instructing them to check it out and link them directly to it. Is there such an app out there? How much would it cost?