UPDATE
OS X El Capitan, macOS Sierra Not Currently Supported on the Modbook Pro
Get more information about which operating systems are supported

What is the Mod Key?
UPDATED: NOVEMBER 23, 2015

The Mod Key is situated beside the Power Button on the input/output panel of your Modbook Pro. It resets the pen tablet and reloads the tablet’s software drivers. To use the Mod Key in OS X® or Windows®:
OS X:
A quick press of the Mod Key is often required after booting into OS X. To use the Mod Key, after you are logged in to OS X just press it down briefly. This will load the pen tablet drivers (with the previously saved calibration settings). You should see the pen tip and cursor come into alignment.
Note: In Yosemite with the Modbook Software Bundle for Yosemite installed, the Mod Key function will usually be automatic as soon as you use the pen, so you may not need to press the Mod Key button.
Windows 7:
The Mod Key is generally not needed in Windows 7 except when transitioning from OS X to Windows 7. In transitioning from OS X, Windows 7 may not recognize the pen tablet. You can tell if the pen tablet is not recognized because there will be no software keyboard on the Windows 7 login screen. To recognize the pen tablet, press and hold down the Mod Key for about five to ten seconds. (You may hear the Windows “bah-dum” sound.) A software keyboard should appear so you can enter your login password. (Optionally, you can click the lower left icon, select “Type without the keyboard [On-Screen Keyboard]” by checking the box next to it, and click OK.)
Once you’re logged in to Windows, you will always know the system is recognizing the pen tablet if the Tablet PC Input Panel appears when you touch the screen with the pen (by default, it is minimized and docked drawer-style on the left side of the screen). If Windows doesn’t recognize the pen tablet, press the Mod Key again by holding it down for five to ten seconds.
Modbook and the Modbook logo are trademarks or registered trademarks of Modbook Inc. in the U.S. and/or other countries. Apple, Mac and OS X are trademarks or registered trademarks of Apple Inc. in the U.S. and/or other countries. Microsoft and Windows are trademarks or registered trademarks of Microsoft Corporation in the U.S. and/or other countries. Wacom and Penabled are trademarks or registered trademarks of Wacom Co., Ltd. in the U.S. and/or other countries. Other trademarks contained herein are the property of their respective owners.