Do I need to redesign my Mac app for MacBook Ultra's touchscreen?

No. Apple's guidance is the opposite: your app should look the same on a Mac with touch and one without. Keyboard and mouse stay the primary input, touch is secondary. Most apps built with Apple's framework controls work with touch right away.

What touch target size should I use on macOS?

36 points. On a Mac display that's the same physical size as 44 points on iPhone. Apple's controls already use it, and the target is invisible: the controls didn't change size, so your layout doesn't change either. For custom controls, enlarge the hit area, not the control.

How do hover actions work with touch?

There's no hover with a finger. Tooltips and other information-only hovers don't need to work with touch. Only the most important hover actions for the content you touch should appear, and every hover action should also be available elsewhere, usually in the context menu.

Can my app use three-finger gestures on the touchscreen?

Not the system ones. Three-finger swipes, thumb-and-three-finger pinches and edge swipes belong to macOS (Mission Control, App Exposé, spaces, menu bar, Dock, Notification Center, Control Center). Apple's "Bring touch to your Mac app" session covers how to work with multi-finger gestures in AppKit, Mac Catalyst and SwiftUI.

Touch on the Mac: Getting Your App Ready for MacBook Ultra

MacBook Ultra is the first Mac you can touch. Apple's human interface team explained in a design session how Mac apps should handle it. The short version: don't redesign anything. Get the gestures right, check your custom controls, and handle hover.

macOS doesn't change

macOS on a touch Mac looks exactly like macOS on any other Mac: same resolution, same window sizes, same text and control sizes. That's deliberate. Keyboard and mouse stay the primary input, and touch is secondary.

So your app should look the same on both. No "touch mode", no bigger layout. What's new is direct manipulation: you reach for a control and it reacts under your finger, without finding the pointer first.

The gestures, trackpad vs touch

Action	Trackpad	Touch
Select	Click	Tap
Open	Double-click	Double-tap
Scroll	Two fingers	One finger
Zoom / rotate	Pinch / rotate	Pinch / rotate, on the object under your fingers
Context menu	Two-finger click	Tap and hold
Drag	Click and drag	Tap and hold, then drag

A few rules come with it:

Tap selects, double-tap opens. Don't copy iOS's "Select" mode. Selection on the Mac is modeless, and touch keeps it that way.
Tap and hold does two things at once. The item scales up under your finger and its context menu appears. Drag away and the menu closes, or slide into the menu and pick an item. Shift and Option still work while dragging.
Several fingers, several controls. Touch can move two sliders at once, as in Logic. The mouse can't do that, and it's what makes an app feel alive under your fingers.

Custom gestures

Make them work with the trackpad too, and with Magic Mouse if possible. Use a modifier key where the gesture clashes. In Maps, two fingers up tilts to 3D on the display, and on the trackpad it's Option + drag, since two fingers there already pan.
Never touch-only. Every gesture's action should also be in a menu or button.
Easy switching between inputs beats iOS parity. Reuse your iOS gestures, but someone moving between trackpad and screen shouldn't have to relearn anything.
Don't rebuild the layout for a new gesture.

Where on the screen

On a laptop, the edges of the display are easy to reach: you grab the side of the screen and your thumb is steady. The center means your arm hangs in the air.

Sides of the window: dense, precise controls such as inspectors and sidebars.
Center: big, rough gestures such as pan, swipe, pinch and rotate.

Gestures that belong to macOS

These are taken by the system, and your app can't use them:

Three fingers up: Mission Control. Three fingers down: App Exposé
Thumb and three fingers pinching in: apps. Spreading out: the desktop
Three fingers left or right: switch spaces
Swipe down from the top edge: menu bar (when hidden). Up from the bottom edge: Dock (when hidden)
Swipe over the Dynamic Island: Siri
Swipe left from the right edge: Notification Center. Down from the top right: Control Center

Keep your important controls away from those edges.

Controls and the 36-point target

36 points is the touch target on macOS. It's the same physical size as 44 points on iPhone. Apple's controls already use it, and the target is invisible, so nothing gets bigger and your layout stays put.
Custom controls: enlarge the hit area around the control, not the control itself. Small controls must still react to touch. A touch should never be ignored.
Sizes stay the same. Medium controls are the default in inspectors, and toolbars use extra large. Large and extra large outside the toolbar only for key moments or content apps (the play button in TV). Small and mini controls still work for dense apps.
Lists and settings: use the form style, which gives rows a 36-point height.
Menus adapt by themselves. Opened by touch, they get slightly taller rows. Your popovers and custom menus can do the same, depending on the input that opened them.

Even very dense apps benefit. In Xcode, touch is handy for scrolling and moving through sidebars.

Hover actions

A finger can't hover, so:

Information only (tooltips): doesn't need to work with touch.
Already easy with touch: hide it. Carousel arrows don't appear during touch, because you can just swipe.
Show only the most important ones. In Safari, touch reveals just two: the current tab's close button and the plus in the address bar. Nothing on other tabs or in the sidebar.
They hide again when you use them, pick up the mouse, or touch outside their area.
Duplicate them elsewhere, usually in the context menu. In Reminders, the hover-only Share button on a list doesn't appear with touch at all, because Share is in the list's tap-and-hold menu.

Small controls expand

Steppers, dials and short sliders are too small for a finger, but making them bigger would ruin macOS's density. Instead they expand in place on touch:

Stepper: a tap anywhere shows large up and down buttons. Tap to step, or hold to keep changing.
Dial: a tap opens a large dial. Drag the knob, or tap and hold and the knob jumps under your finger.
Short slider: a tap expands it to full length. Tap and hold expands it with the knob under your finger.

The first tap never changes the value. Expanded controls collapse when you stop, or when you tap outside. You get this for free with Apple's controls. Custom ones need the same behavior.

Checklist

No visual changes for touch: the same app on every Mac
Tap selects, double-tap opens, tap and hold shows the context menu and drags
One-finger scrolling works in every scroll area, including custom ones
Custom controls have a 36-point hit area and never ignore a touch
Custom gestures also work with the trackpad and are duplicated in a menu
Hover-only actions are also in a context menu
Precise controls near the window edges, big gestures in the middle
Keyboard and mouse still come first

Show the new Mac in your App Store page

If touch makes your Mac app nicer to use, show it in your App Store preview video. App Preview Studio turns a screen recording into an App Store preview, header or search results video in minutes, not hours in a video editor.