The “new tool” thread now applies to Havannah. You can access the analysis site at

https://minortriad.com/ahexlg.html

Input the number for your game.

This is not an engine. The site does not recognize a winning position. You label the leaf nodes as advantage or disadvantage, and the rest of the nodes are updated automatically. You can save your work to your machine and merge that file with later analysis. See the thread for more details.