Why Doesn't this App Exist?

Surely this app exists, but for the life of me I can't find it on Google Play:

I'm after a simple messaging app that allows one phone to trigger an arbitrary set of vibrations on another phone. The setup would work like so:

• Phone A: the receiver opens up the app, where it displays the device's unique ID
• Phone B: the sender, plugs in this ID into his app
• Phone B: the sender, identifies a series of buttons he'd like to see on the app. Each button has a label as well as a vibration pattern (see also: here) associated with it

Now, anytime a button is pressed on Phone B, Phone A would vibrate to said pattern.

Why do I need such an app? So many reasons. But essentially it allows for quick, silent and long distance communication where the receiver doesn't even need to look at their phone.

Thinking about it, it's basically a digital telegraph, though using vibration instead of sound.

Approximating this app is quite simple in Tasker AutoRemote, so I may just end up doing that as a prototype. Though, that does mean buying Tasker and AutoRemote for the client phone, which all things considered isn't too expensive.

Still, how can this app not exist?

I'll give this a few days, if I'm still craving the app, maybe I'll just write it.