AFAIK at the moment only package manager is on “Packages” page in the web interface.
Just recently there was package “A Kit of Utilities and Services 1.0.0”
And some other Add-ons
If there program needed is not in that list then only solution is to hack it together yourself. I have managed to add some programs by compiling them from source on CentOS machine. Compiling must be done statically!
And then I copied programs to zeroshell and added them to path.
In script editor I added path to Post-boot script: