@francescogola
It does, in fact, remain possible to use plugins on a phone within a browser. This is a section that I added to the installation note for my plugin covering this. I think it is quite likely that your plugin will also work in this way. I hope this is helpful...
Mobile
Note: Windy plugins including SoarCalc are not compatible with the Windy mobile App but SoarCalc functions well within Chrome etc on mobile devices.
Open Chrome or other browser on your mobile device.
Navigate to "windy.com/plugins" (do not go to windy.com as that will redirect you to the App which you do not want)
SoarCalc should appear in the list of available plug-ins. If so simply select it, otherwise please follow Load plugin directly from URL.
The plug-in is now installed. However, it is not yet available in this browser tab so close this tab.
Navigate to "windy.com/plugin/soarcalc" in a new window/tab and SoarCalc will appear at the bottom of the screen.
It will always be necessary to use "windy.com/plugin/soarcalc" so you may want to create a shortcut to that.
Ignore the button inviting you to "Download App".
Load plugin directly from URL
If "SoarCalc" is not found in the list of plug-ins then it is still possible to install directly from the URL...
Select “Load plugin directly from URL”
Paste this string after the url already present in the input box:
12216047/windy-plugin-soarcalc/1.0.5/plugin.min.js
Press "install untrusted plugin" and SoarCalc will be available on the main menu.