I also use Fork and find it the fastest and easiest git GUI. And I tried so many GUIs in the past. One thing that works well in Fork is submodules, which are almost non-existent in other GUIs. And the UI is really fast to respond.
On a side note, regarding the licensing. As a software vendor selling to enterprises, I always struggle with finding this kind of information. Would you be willing to briefly explain how large enterprises usually buy software or subscriptions? It would help me/us so much.