Which questions do you not understand, the first or the second? As for the 1st question, the Contact tab at the bottom of the CCM page leads to a menu that includes the selection "Establishing a partnership" and that selection leads to what appears to be a submission form for providing the links to programs that you might consider for inclusion on your download list.
That submission form under the phrase "How to upload programs to CCM" includes the requirements for a JPG logo image and a software screenshot. I didn't see any buttons for message picture attachments but to make a long story short I'm just going to provide links to those required pictures in the submission message box if that's okay.
The 2nd question refers to a "digital signature certificate" and I assume that you know what that is but if not then I suggest that you do a Google search for that term. My program doesn't yet have one of those and I didn't know if you required it for the programs you endorse. Digital signature certificates are important to Microsoft, Windows and other folks but they have no effect on how well a program operates. They simply provide assurance against malicious activity.
I'm a software programmer who belongs to several forums but this is a new forum for me and I'm trying to understand how things are done here. It would help me if you could be a little more specific about what you don't understand. Otherwise I'll just submit my program suggestion as best I can. Thanks.