Staff Pick: Display Maestro
Display Maestro is a menubar add-on that gives you enhanced control over the displays you have attached to the computer (both external and internal). By default Apple keeps display settings simple, and only provides those that are supported by the manufacturer and the operating system. By ignoring the manufacturer's limits, Display Maestro enables a variety of custom resolutions and color bit depths, as well as scan and refresh rates which allow for fine-tuned customization of the displays. Please note that while this can be exceptionally beneficial for certain applications and situations, take care in how you customize these settings since some can be potentially unsafe for the display.