See

https://www.toketaware.com/blog/2017/2/27/ithoughts-for-windows-is-live

One of the best mind mapping apps on the Mac platform is now available for Windows too.

Not as fully featured as the Mac or iOS versions though -- the export options especially and the integration of the Mac version with macOS Safari is not carried over. It works, but is more along the lines of a "reader" version.

Paul Korm wrote:

Not as fully featured as the Mac or iOS versions though -- the export
options especially and the integration of the Mac version with macOS
Safari is not carried over. It works, but is more along the lines of a
"reader" version.

I really enjoy the Windows version and am productively using it, would not call it a "reader". Comparable to Scrivener on Mac vs. Windows - Mac does more, but both are useful in their own right and especially for cross-platform work.
The author has been very good adding new features to the Mac and iOS versions over time, I'm sure the Windows version will evolve similarly.