Yes, you can import gedmatch matches into genome mate, both individually and in bulk (limit 200) that are pulled out via triangulation tool on gedmatch..instructions on how to do each are given in the application itself and are very straightforward and easy to follow.

If you use the chrome DNA helper extension for ancestry.com, you can add those to the data base, but they won't have the actual data attached so you have to match them to the gedmatch, 23&me or FTDNA raw data that you upload. It is a painstaking process but if you have communicated with an ancestry match who tells you their gedmatch kit number, it is easy.

FTDNA data is very easy and has user names; 23&me data a little more work, but they transfer as well.

Don't know why you don't see the download button for the application itself. Maybe you have to have silverlight first. Hope that is helpful.