MoonBehavior is a great Behavior Tree solution with a nice Visual Editor
Features:
-Multi-use: Create reusable AI behaviors and/or logic with minimum coding.
-Unity friendly: MoonBehavior stores everything into ScriptableObjects, you will be able to export to any unity platform without any serialization issue.
-Local Memory: Store/Get Variables and information for each AI GameObject using the Memory property.
-Realtime Debugger: Debug the logic of your behavior trees using the realtime debugger that allows you to visualize the execution, and data of your behavior trees in realtime.
-Source code included: You will get all source code (documented ) including the editor side that allows you to modify MoonBehavior to your needs if you want to.