With the 2.0 update for Space Replicator, we have included a standalone app.
Installation
To install the app, download the latest installer and follow the installation instructions.
Setup
To get set up, open the standalone app and click the gear icon in the top right.

Click on the output device dropdown and select the output you want to use for the standalone app.

Click on Connect to use Space Replicator for that output device.

The Standalone status shows the currently active connection.
To bypass Space Replicator, use the bypass toggle in the top right.
To disconnect Space Replicator from your output device, click on Disconnect.

Windows-specific options
Registry
On Windows, you need to set a registry entry to use the APO (Audio Processing Object). In most cases, this should happen automatically. If it worked, you can see "Registered" in the Standalone APO section.
You only need to set this once, with admin privileges. If you encounter a problem, click "Fix registry".

Why do I need admin rights on Windows?
To change the audio stream in Windows, admin privileges are required. Therefore, Space Replicator standalone needs admin rights to function. The admin rights are only used to insert Space Replicator into the audio output, for nothing else.