ZUV Tools Add-On
Zach Eastin writes:
ZUV Tools extends Blender’s UV toolset with some powerful selection, spreading, smoothing, and manipulating tools. Bringing over tools such as smooth, find shortest path, circle, relax, and many more ZUV Tools gets you working faster than ever!
Hello all! If you’d like to try before you buy 1.0 is free to download on Gumroad : https://gum.co/hMdCS
2.0 is on Blender Market for $5. Check Gumroad to see the differences between the 2 versions. 1.0 has basically all of the tools, but also has bugs and is slower than 2.0.