Anything you type on your mac keyboard when this dialog is on the screen will go to the connected phone/device over bluetooth. Use the shortcut key Command-option-p which is the hotkey to launch the application.
We have added the ability to send media control commands to the connected device. Let us know what your think.
Additionally
The app connects to your phone/tablet/TV only when the keyboard screen is launched (by pressing command-option-p). If you switch to another app on your laptop/desktop the window will disconnect and close. This may seem weird at first, but there are going to be so many times that you take your phone and walk away. If the app did not automatically disconnect (when your laptop screen saver came on) you would be very frustrated, because you need to disable Bluetooth on your phone to start typing on your phone.