Sidecar

Sidecar, stylized as "Sidecarx", is a program and applet developed by Apple Inc, first introduced in macOS Catalina and iPadOS 13.

Usage
Sidecar allows you to show what's happening on your Mac, broadcasting it on your iPad, yet it still allows you to use Apple Pencil on the device. This allows a simple, clean multitasking environment. It acts like a second display for your Mac.

How to access
On a Mac, click on. Then, you can move the sidebar to the left or the right of the screen, move the Touch Bar to the bottom or the top of the screen, or enable double tap on Apple Pencil.

Critiscm
Though the critiscm is not as extreme as the iOS 6 or 7 ceitiscm, Sidecar still recieved some poor reviews. When updated to macOS Big Sur, Sidecar would fail to boot, and you would need to manage your plug-ins or change your iCloud password to get it right.