LeafData is the system designed and developed by MJ Freeway. It is deployed in Pennsylvania and Washington. Nevada used this system for a short time before is was replaced by METRC.
In Pennsylvania the system is for medical cannabis only and is managed by the Department of Health. This sytem does not provide any API/external access.
In Washington the system is for medical and recreational cannabis and is managed by the Liquor and Cannabis Board. This system does provide an API, there are over a dozen integrated providers.