Why there is not a option just to add a friend ?

I gotta agree on this one, feels very weird and clunky.

-Naiguli

The client is supposed to be a portable version of the website. The website lacks this feature, therefore the Galaxy client also lacks it. It was someone's bright idea to try to make the 2 completely interoperable and so you can't get things you'd expect to see in it until they fix everything.

The 1.1 update to Galaxy will be coming very soon as an early preview. Likely next week or the week after (assuming they don't push it out for the weekend). The feature should be part of that update. I would assume it will also come to the site when it leaves early access or maybe even during the early preview.

I just want Galaxy to remember or check what it downloads so it doesnt re-download a 2GB file that i already have in chossen download location.

GOGdownloader never re-downloaded the same file.