Explaining specific so you don't need a third-party app at all.
Consider the scenario of a user consuming high-bitrate video content. Standard settings might throttle the display to conserve energy. However, an ADB-controlled extended key could allow the user to instantly switch the display to its native "extra quality" mode—bypassing software throttling to reveal the full capabilities of the panel. Conversely, another key could be mapped to lower the resolution and refresh rate for reading, extending battery life without navigating through cumbersome menus. This dynamic control transforms the device from a static product into a fluid instrument. adb appcontrol extended key extra quality