Thank you Tim for your answer, I assumed that...

I discovered that the instrument shows up if:

- in "landscape view" you have to turn of at least one other instrument (you can view only 5 instruments)
- in "portrait view" you have to turn off 2 other instruments (you can view only 4 instruments)

I use the MD in portrait view, so it's explained why I couldn't see the wind instrument even if I turned off one like in the image I linked...

It works the same as it does on the PC, iOS and Android versions. It shows the wind, or the headwind, assuming that you have synced wind forecast data which is valid for the time of your flight.

Ok!