Sync and backups

Someone with two Macs almost always wants the same groups on both. Discovering afterwards that a setup you built on the laptop never reached the other machine is worse than syncing something you would have shared anyway, so Share groups across my Macs is on by default.

What travels, and what does not

Only the library travels: the groups themselves, and the record of which ones were deleted.

Everything about this machine stays on this machine. Which group is active, and every setting in Settings, are per Mac and deliberately not shared. A machine in a rack and a laptop want the same library and emphatically not the same active group.

How two Macs agree

Every group carries the date it last changed. When two machines hold the same group, the newer copy wins. Reordering the sidebar does not count as a change: order is a property of the list, not of the group, and reordering on one Mac should not out-rank a real edit on the other.

Deletion is the harder half. An absence cannot travel: without a record, a group deleted on one Mac simply reappears from the other on the next merge, forever. So a deletion is recorded with its date, that record travels, and a later re-creation of the same group wins over an older deletion. The records are pruned once every machine has certainly seen them.

When it does not work

Sharing needs three things: an entitlement, a signed build, and a user signed in to iCloud. Any of the three can be missing, and when one is, Settings says which in a plain sentence and everything else keeps working against the local file.

A build you compiled yourself will report sync as unavailable, because the entitlement counts only when the bundle embeds a provisioning profile that grants it. That is expected, not a problem with your machine.

# echo 'Share groups across my Macs'
Last synced 20 August 2026 at 09:14
iCloud is unavailable: no iCloud account is signed in

There is a Sync Now button for when you do not want to wait for the background pass.

Backups

Sync solves one problem and creates another. A merge that resolved the wrong way, or a group deleted on the wrong machine three days ago, is not something a single previous version can recover. That needs history, and history needs dates.

The app keeps dated copies of the whole configuration. Each one is listed with when it was taken and how many groups it holds, so restoring is a choice rather than a gamble on a filename.

$ ls -1 ~/Library/Application Support/MoreDisplays/Backups | tail -4
config-2026-08-17-091402.json
config-2026-08-18-183311.json
config-2026-08-19-074455.json
config-2026-08-20-091401.json

Backups are plain configuration files with a timestamp in the name. Anyone can read one, copy one off the machine, or hand one back. A backup format only this app can open is a backup nobody trusts.

Back Up Now takes one on demand. Restore puts one back, and takes a backup of the current state first, so restoring the wrong one is itself recoverable.

Turning it off

The switch in Settings turns sharing off. Nothing already published is deleted from your own iCloud by turning it off, and nothing new goes up. The local file keeps working exactly as before.

Nothing here leaves your own iCloud account, and there is no server belonging to this project. See Privacy.

Next

• Groups for what a group holds in the first place.
• Uninstall for removing all of it, including the backups.