There is a wide range of Apps for your 123-reg Hosting Package, but they all follow the same install method.
To install a 123-App to your 123-reg hosting package, please do the following:
Log into your 123-reg control panel.
Scroll down to the Web hosting section, select the relevant domain name in the drop-down box and click on the Manage button.
Scroll down to the CGI Script section and click on the application you wish to install.
Enter a name into the field to create a directory to install the application to. Once filled click the Install Now button.
Please note: If you wish to install an application to the root directory please leave the field blank.
The application will now install, this may take a few minutes.
When the application is successfully installed you will see this page. You can now start to use the application you have installed.