You only need to install one copy of SQL Clone Server, however many servers you want to perform SQL Clone operations on. SQL Clone Server is a web app, so it must be installed on a machine that is visible from everywhere you want to use SQL Clone.
After running the installer, a setup utility runs to configure SQL Clone Server:
This will configure and start the server. The server's web app uses Windows authentication, so log in with your Windows credentials.
The URL will be of the form: http://machine-name:14145. On this machine there'll be a start menu shortcut, but you'll need to share the link with other users who want to access the web app from other devices.