I still use UV Mapper Pro to test that UVs remain intact if I make changes while creating content, but it appears to me that there haven't been any updates since 2016 and the link to purchase goes to a non-existent store. While it still works, and does work under Win 11, there are other options that are much more powerful.

My UV weapon of choice is Rizom UV Virtual Spaces, which is amazing.   https://www.rizom-lab.com/rizomuv-vs/  The perpetual license is 150 (euro)

Others use Headus UV Layout www.uvlayout.com  which is roughly the same price. Maybe a tad higher than Rizom.

Your modeling software more than likely has UV mapping features as well, if you have one.