Guys,
I'm well aware of the situation regarding Windows Phone/Mobile and its "app gap", thank you very much.
I've had my latest Windows Phone (Nokia Lumia 830 under Windows 10 Mobile) for 2 years and a half now, way long before I even knew Amazon Echo existed.
My question was to know if there was a workaround, which I'm afraid there isn't, for Windows users (desktop or mobile, app or website).
Anyway I live in France so even if I had the proper smartphone/app, I guess the feature would not be available yet over here for technical/geographical reasons (the Echo not being available itself to start with).