Simulator

When Simulator is one of a workspace’s apps, its Work context row lets you choose a device, an app installed on it, and an optional link. Launch layout then boots the device, opens your app, and places the device’s window in Simulator’s zone.

Layout uses Xcode’s simulator tools, so Xcode must be installed and selected with xcode-select.

Set up the context

Click Simulator’s row (Choose a device until it’s set) and fill in:

• Device: a specific simulator device, Shared simulator, or Launch Simulator only.
• App bundle ID: the bundle ID of an app already installed on that device, such as com.company.app.
• Link (optional): a link to open in the simulator after the app, such as myapp://settings, or an Expo development build link like exp+myapp://expo-development-client/?url=….

Launch Simulator only removes the context: Launch layout then just opens Simulator.

The bundle ID must look like com.company.app. The link needs its scheme and ://, and no spaces: “Use a complete link with its scheme, such as myapp://settings or https://….” The link opens inside the simulator, not on your Mac, so any scheme an installed app handles works.

Layout never builds or installs your app. Install it on the simulator once, from Xcode or your usual tools.

Choose a device

The Device button opens a searchable list:

• Type to filter by name, OS version (26, iOS 18), or state (booted). Every word must match, so pro 26 finds an iPhone Pro on iOS 26.
• Use ↑ and ↓ to move, Return to choose, and Esc to close.

Each device shows its OS version, and “Booted” when it’s running. iOS devices come first, newest version first. The ↻ button next to the list reloads it, for example after you create a new device in Xcode. A device that no longer exists stays listed as “Unavailable”, so you can see what was saved.

Shared simulator

Shared simulator lets several workspaces use one device that you choose in a single place: Settings › Apps › Shared simulator. Changing it there moves every workspace set to Shared simulator to the new device.

Until you pick a shared device, the option reads “Shared simulator (not set)”, and the row warns: “Choose the shared simulator in Settings, or pick a device.”

What Launch layout does

1. Boots the device if it’s off. A cold boot can take a while: Layout waits up to two minutes.
2. Shows the device in Simulator.
3. Launches your app on it.
4. Opens the link, if you set one.
5. Places that device’s window in Simulator’s zone.

Layout recognizes the device’s window by the device name in its title. It matches the whole name, so iPhone 17 Pro never takes the window of iPhone 17 Pro Max. If two Simulator windows have the same device name, Layout shows an error instead of picking one.

Simulator doesn’t let other apps resize its windows. The window goes to the top-left corner of its zone without necessarily filling it. If Simulator is a floating app, its card takes the size the device window keeps, and can lock to its proportions.

When you switch workspaces

Switching workspaces never boots a simulator.

When several workspaces use the same device, through Shared simulator or by choosing the same device, switching to one of them brings its app to the front, as long as the device is already booted. The app isn’t restarted if it’s still running, and the link doesn’t open again: links only open with Launch layout. If you switch quickly several times, only the last switch counts.

A device used by a single workspace receives nothing when you switch.

Errors you may see

Message	What to do
Could not list simulators… Check that Xcode is selected with xcode-select.	Install Xcode, or select it with xcode-select.
(device) is still booting. Retry Launch layout once it is ready.	Wait for the device to finish booting, then launch again.
(device) no longer exists. Choose another simulator in Work context.	Pick another device.
Could not launch (bundle ID) on (device)… Install it on this simulator once, then retry Launch layout.	Install your app on that device, then launch again.
(device) could not open (link)… Check that an installed app handles this link.	Check the link, and that the app that handles it is installed.
Several Simulator windows show (device). Shut one down or rename it in Xcode, then retry Launch layout.	Keep a single window for that device name.
The (device) window did not appear in Simulator. Open it from File › Open Simulator, then retry Launch layout.	Open the device’s window in Simulator, then launch again.