Since its release, ElumTools has been continuously updated to be compatible with the latest available Revit version. We have been fortunate to be able to include all current capabilities in the most recent three major versions. Licensed ElumTools users have access to, and can use all three. The version of ElumTools will work with its corresponding version of Revit. For example ElumTools 2019 works with Revit 2019.
Note that Add-ins are not available in Revit LT so ElumTools cannot be used with that product.