DuoBook

Support

Something not working? Most answers are below. If not, write to info@mehdichitsaz.com with your iPhone model, iOS version, and Mac’s macOS version.

Getting started

  1. On your Mac (macOS 14 or later), install DuoBook Host and open it. It lives in the menu bar.
  2. Allow Screen Recording and Accessibility for DuoBook Host. Its setup window opens by itself with an Allow button for each: click it, then turn on DuoBook Host in the list System Settings shows. After Screen Recording, click Reopen DuoBook Host. (Later, the same buttons are in DuoBook Host’s menu-bar menu.)
  3. On your iPhone, open DuoBook and allow Local Network access. Keep both on the same Wi-Fi.
  4. Tap your Mac under Nearby. Check that both screens show the same 6-digit code, then click Pair on the Mac.
  5. Tap Connect. On iPhone Duo, fold it like a laptop.

Common questions

The Mac’s screen is black or doesn’t appear

DuoBook Host needs Screen Recording permission. Open System Settings → Privacy & Security → Screen & System Audio Recording, turn on DuoBook Host, then quit and reopen it.

I can see the screen but typing and clicking don’t work

DuoBook Host needs Accessibility permission to type and click for you. Open System Settings → Privacy & Security → Accessibility and turn on DuoBook Host. If it’s already on, turn it off and on again, then reopen DuoBook Host.

My Mac doesn’t show up under Nearby

Make sure both devices are on the same Wi-Fi network and DuoBook has Local Network access (iPhone Settings → Privacy & Security → Local Network). Some guest and office networks block devices from seeing each other; use “Pair by address…” with the address DuoBook Host shows in its menu (“On this network at …”).

How do I use it away from home?

In DuoBook Host, turn on Access from anywhere and connect once at home. DuoBook Host asks your router to let DuoBook in (most home routers allow this with UPnP or NAT-PMP turned on; how to turn it on) and keeps your Mac’s address in your own iCloud, so your iPhone finds it from anywhere. Both devices should use the same Apple Account for iCloud. Set Keep Mac awake to “When plugged in” (or “Always”, which works on battery too but drains it faster) so the Mac doesn’t sleep. Closing a MacBook’s lid still puts it to sleep.

It works at home but not away

Check DuoBook Host’s “Access from anywhere” status. If it says your router didn’t allow it, turn on UPnP or NAT-PMP in your router’s settings: here’s how, router by router. Some internet providers share one public address between many homes (called CGNAT); then direct access can’t work, and you can run a relay server instead and turn on “Also use a relay server” in DuoBook Host.

Three-finger swipes don’t work

iPhone’s Zoom feature (Settings → Accessibility → Zoom) reserves three fingers. Turn Zoom off, or swipe with four fingers, which does the same thing. Mission Control and desktop switching use the Mac’s standard shortcuts (control + arrow keys); if you changed those in System Settings → Keyboard → Keyboard Shortcuts, set them back.

The Touch ID key locked my Mac. How do I unlock it?

With DuoBook Host 1.1, your iPhone shows the Mac’s lock screen: type your Mac’s password on DuoBook’s keyboard and press return. It works away from home too. With an older DuoBook Host, unlock it at the Mac (password, Touch ID, or Apple Watch); update DuoBook Host to unlock from your iPhone.

Can I type emoji or other languages?

Yes. Tap the … button → Type text, and use the iPhone’s own keyboard, including dictation. A Bluetooth keyboard paired with the iPhone types on the Mac too.

Where do photos and files I send go?

Into the Mac’s Downloads folder. Use … → Photos & Videos or Files.

Is it secure?

Pairing happens once, on your own network, with a code shown on both screens. Every connection is encrypted end to end with keys only your iPhone and Mac have. DuoBook collects no data. See the privacy policy.

Can I try it without a Mac?

Yes. On the home screen, tap “Try the demo — no Mac needed”. It runs a pretend Mac on your iPhone.