Download Umbra

Windows

Because the app is not yet signed, Windows SmartScreen may warn that it protected your PC; click More info, then Run anyway.

Keep the default install location. The installer lets you choose where to install Umbra, but keep the default (%LOCALAPPDATA%\Umbra). Automatic updates work by replacing Umbra's own folder, which is only possible where it can write without administrator rights: installing elsewhere, in particular Program Files, will break updates.

macOS

Because the app is not yet notarized, macOS blocks it on first open with a message that it could not verify the package. To allow it:

1. Click Done on the warning (not Move to Trash).
2. Open System Settings → Privacy & Security.
3. Scroll down to the Security section, find the message about the .pkg, and click Open Anyway.
4. Confirm Open Anyway and enter your password when prompted.

Open Umbra from Spotlight (press ⌘ + Space and type Umbra) or from Launchpad. The installer puts it in the Applications folder inside your Home folder, which is not the Applications shortcut in the Finder sidebar (that one is the system-wide folder). Leave it there: moving it elsewhere, including into the system Applications folder, will break automatic updates.