The AbleNet TrackerPro 2 is a hands-free mouse that allows you to use small head movements to move the mouse cursor. It also provides hands-free left and right clicking when you enable Dwell Control in macOS Mavericks 10.9 or later. Or you can connect accessibility switches such as the AbleNet Jelly Bean Twist or AbleNet Specs Switch for left and right clicking.
In addition, TrackerPro 2 is compatible with an iPhone or iPad that's using iOS 13 or later or iPadOS and has AssistiveTouch turned on. You'll also need a USB-A adapter, which is sold separately.