the author of this app says:
Ministro is a system wide Qt shared libraries installer/provider service. It acts as a bridge between your apps and Qt libraries.
Ministro service is release under GPL v3+ license.
The connection API protocol used by applications to connect and query the service is released under BSD license, it mean that any application (no matter if that application is free or not) can connect and query its services.
Also, be aware, this service will install/provide the free versions of Qt libraries, licensed under LGPL v2.1/ GPL v3.