Are there ways to modify or customize the apps that appear on the home screen of HCL?

Yes - the home screen will always come with core default applications that cannot be moved or changed, but you have a lot of flexibility on what to add.

To add an application, simply press the "plus" icon on the home screen and choose the application from the application list.

To remove an application, simply long press the application on the home screen and indicate that you would like to "delete" that short cut.