Installers for Continuum can be found here: Boris FX | Downloads
As you will see on the above page link, there are separate installers for each host API and for each OS platform, so if you need to install Continuum in more than one host, or on both Mac and Win OS, you’ll need to download the specific installer for that host / OS and run it.
The totally free Continuum Looks FCP plugin can be downloaded here: Continuum Looks FCP