"A unique, memorable icon expresses your app’s or game’s purpose and personality and helps people recognize it at a glance."

"In iOS, iPadOS, and macOS, icons are square, and the system applies masking to produce rounded corners that precisely match the curvature of other rounded interface elements throughout the system and the bezel of the physical device itself."

Source: Apple https://developer.apple.com/design/human-interface-guideline...

lol