FocusFixer

Native macOS menu-bar utility that fixes a long-standing multi-display bug: after clicking a window on one screen, keyboard focus can stay on a window on another screen, so typing goes to the wrong place. Download, unzip, run — grant Accessibility when prompted (see CLAUDE.md for how the app is built).

Installing from a downloaded release

Grab FocusFixer-vX.Y.Z.zip from the releases page, unzip it, and drag FocusFixer.app to /Applications.

The app is signed with a self-signed identity (sttlab-apps), not an Apple Developer ID — there's no paid Apple account behind this project. macOS's Gatekeeper doesn't trust that signature by default, so on first launch of a version downloaded from a browser (which macOS marks with a quarantine flag) you'll likely see it refuse to open, or ask to move it to the bin. Pick one of the two options below to get past that — you don't need both.

Option 1 — Trust the sttlab-apps certificate

This tells your Mac to trust anything signed by this specific certificate going forward, so you won't need to repeat this for future versions of the app (as long as it keeps being signed with the same identity).

1. Get the certificate: sttlab-apps.cer (ask for it, or export it yourself if you have access to the machine it was created on: `security find-certificate -c "sttlab-apps" -p

   sttlab-apps.cer`).

2. Import it into your login keychain:

   security import sttlab-apps.cer -k ~/Library/Keychains/login.keychain-db
   

3. Trust it, but only for code signing (not as a general root CA):

   security add-trusted-cert -r trustRoot -p codeSign \
     -k ~/Library/Keychains/login.keychain-db sttlab-apps.cer
   

   macOS will prompt for your login password — that's it asking permission to change keychain trust settings, not this command asking for a password directly.
4. Open FocusFixer.app normally (double-click, or open /Applications/FocusFixer.app).

Option 2 — Bypass Gatekeeper for this app only

No trust changes, no certificate needed — just tells macOS to stop flagging this specific app. You'll need to repeat this for each new version you download (the quarantine flag is set per downloaded file).

Either:

• Right-click FocusFixer.app in Finder → Open → Open again in the confirmation dialog. (Regular double-click won't offer this the first time; right-click → Open does.)

Or, from a terminal:

xattr -dr com.apple.quarantine /Applications/FocusFixer.app

(-r because it's a bundle — the quarantine flag can be set on files inside it too, not just the top-level .app.)

Both achieve the same result: the app opens. Option 1 is the better choice if you expect to download future versions and don't want to repeat the bypass each time; Option 2 is faster for a one-off.

Granting Accessibility permission

FocusFixer needs Accessibility access to watch clicks and reassert focus — it can't do anything useful without it. On first launch it prompts for the grant automatically; if you miss the prompt or need to re-grant it later, go to System Settings → Privacy & Security → Accessibility and enable FocusFixer there.

FocusFixer has no Dock icon and no regular window — look for its icon in the menu bar. That menu is also where you toggle it on/off and enable/disable launching at login.