There are thousands of download sites that will list your software. A few, like CNET and Tucows, will host your files for you and count the downloads. Most of these sites require you to build a PAD file (Portable Application Description) for your software before you can list software on their site.
Except for the largest sites (CNET & Tucows) virtually all of these software download sites are a waste of time. They only exist to use your content (the descriptions you build in your PAD file) to sell Google ads. They use automated software to read your PAD file, post a page with that information, and then sell Google ads based on the content in your PAD files. Many don't even include links back to your web site.
One other thought- if the text in your PAD file matches the text on your web pages, then Google will see duplicate content on the web, and ranking of your web page will suffer. Keep that in mind when writing the descriptions for your PAD files.