Install, update and uninstall

What you need

• A Mac with Apple silicon (M1 or later). Intel Macs aren’t supported, and macOS won’t open JimiOS on one.
• macOS 13 Ventura or later.

Why macOS warns you

The beta is ad-hoc signed and not yet notarised by Apple. macOS can’t check it, so the first time you open each build, you confirm it once in System Settings. Every new build has a new signature, so you confirm again after each update.

Install

1. Download and open the disk image (JimiOS-Alpha-0.1.0-12-beta12.dmg).
2. Drag JimiOS Alpha onto Applications.
3. Open it from Applications. macOS says it can’t check it: click Done.
4. Open System Settings → Privacy & Security, scroll down, and click Open Anyway next to JimiOS Alpha. Confirm with your password. The button appears for about an hour after step 3.
5. When JimiOS asks, turn it on in Privacy & Security → Accessibility. JimiOS starts tiling a moment later; look for J1 in the menu bar.

On macOS 13 and 14 you can also Control-click the app and choose Open. Apple removed that shortcut in macOS 15.

What happens on the first open

JimiOS shows a few short boxes, one at a time:

• Another tiler running. If AeroSpace or yabai is running, JimiOS says so and quits. Quit the other tiler and open JimiOS again.
• Running from the disk image. If you opened it straight from the disk image, it asks you to drag it to Applications first, then quits.
• Welcome. A tick box, “Open JimiOS when I log in”, starts unticked. Click Quit here to stop without changing anything.
• Two or more displays. If “Displays have separate Spaces” is on, JimiOS offers to open Desktop & Dock settings so you can turn it off. It never changes the setting itself.
• Accessibility. macOS asks for the permission.

JimiOS also clears the download flag (quarantine) on its own copy in Applications. That never needs a password.

Permissions

• Accessibility is the only permission JimiOS needs. It uses it to move and resize windows and to see its own shortcuts. JimiOS waits up to five minutes for you to allow it, then quits without moving anything. Open it again to retry.
• Say no to anything else. If macOS asks for Input Monitoring, Screen Recording, Automation or Files and Folders for JimiOS, choose Don’t Allow and report it as a bug.

Update to a new build

1. Quit JimiOS from its menu (Quit JimiOS Alpha). That puts every window back on screen first.
2. Open the new disk image and drag JimiOS Alpha onto Applications. Choose Replace when Finder asks.
3. Open it from Applications, then repeat Open Anyway (Install, steps 3 and 4).
4. Turn Accessibility on again if JimiOS asks (Install, step 5).

Your settings and learned window sizes in ~/Library/Application Support/JimiOS Alpha are kept.

Accessibility usually needs granting again after an update. macOS ties the permission to the exact build. The switch in System Settings can look on while it no longer works: JimiOS keeps waiting, or J1 appears but nothing tiles. On the first open of a new build JimiOS notices this and offers Reset and Ask Again, which clears only its own old entry. Click it, then turn JimiOS Alpha on when macOS asks. To do it by hand, see Accessibility is on but nothing tiles.

Check which build you have

The version and build are in the disk image’s name and in its “Build info.txt”. To read them from the installed app, paste this into Terminal (it only reads):

plutil -extract CFBundleShortVersionString raw "/Applications/JimiOS Alpha.app/Contents/Info.plist"; plutil -extract CFBundleVersion raw "/Applications/JimiOS Alpha.app/Contents/Info.plist"

The first line is the version (0.1.0), the second the build (12).

Uninstall

1. Click J1 in the menu bar and choose Uninstall JimiOS….
2. Click Uninstall (Cancel is the default). If you have a settings file, a tick box also deletes it; otherwise the file stays.

JimiOS quits the normal way, putting every window back. It then removes its login item, its own entries in Privacy & Security, and its own files and settings, and moves the app to the Bin. The log stays in /tmp/jimios-alpha until the Mac restarts, in case you want to send it.

If a window couldn’t be put back, JimiOS removes nothing and says so in the log. Open JimiOS, quit it from its menu, then uninstall again.

Uninstalling doesn’t change macOS settings back. If you turned off “Displays have separate Spaces” for JimiOS, turn it on again in System Settings and log out and in.

If JimiOS won’t open, remove it by hand:

1. Drag JimiOS Alpha from Applications to the Bin.
2. Remove it from Privacy & Security → Accessibility with the minus button.
3. If you chose Open at Login, delete ~/Library/LaunchAgents/au.com.softwired.jimios-alpha.login.plist.
4. Delete the folder ~/Library/Application Support/JimiOS Alpha.

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