Hello @Michael-Katzenberg, you should use the same account (email and password), where you already have your Premium account assigned. If you have any problem with activating the Premium, please check this post. Also, I have to mention that we are Windy.com with the red logo and any other apps with anyhow similar name are not ours.

@guntorwe Hi, firstly, Windy.app with the blue logo has nothing in common with us, Windy.com. According to our Premium, it is possible to use one subscription on multiple devices.