Monitorian is a desktop tool to adjust the brightness of multiple monitors with ease. The user can change the brightness of monitors, including external ones, either individually or in unison. For the system with an ambient light sensor, the adjusted brightness can be shown along with configured one. To control an external monitor, the monitor must be DDC/CI compatible and the function enabled. If a monitor is connected through an converter, docking station or other device, such a device must be also compatible. At least, Surface Dock works. In contrast, an USB to HDMI/DisplayPort converter which supports DDC/CI is not yet known to exist. Add-on features are available on a subscription basis. Those features include the following: - Customizable hot keys and shortcut keys - Control over monitors more than 4 Add-on features will not affect the function to recognize monitors. It is advised to check if those functions work as intended during the trial period.