Software as a Service as defined by NIST overlaps considerably with Service as a Software Substitute, which mistreats the user, but the two concepts are not equivalent.
These different computing practices don't even belong in the same discussion.
Likewise, a program developed by a school or an individual can be free or nonfree, depending on its manner of distribution.
The two questions—what sort of entity developed the program and what freedom its users have—are independent.
Instead of with free software, the public has access to the program, we say, with free software, the users have the essential freedoms and with free software, the users have control of what the program does for them.
We don't describe free software as an “alternative” to proprietary, because that word presumes all the “alternatives” are legitimate and each additional one makes users better off.
When the purpose of some program is to block advertisements, “ad-blocker” is a good term for it.
In most scenarios, that is foolish because it exposes you to surveillance.
Another meaning is accessing your own server from your own mobile device. The NIST definition of "cloud computing" mentions three scenarios that raise different ethical issues: Software as a Service, Platform as a Service, and Infrastructure as a Service.
However, that definition does not match the common use of “cloud computing”, since it does not include storing data in online services.
Another meaning (which overlaps that but is not the same thing) is Service as a Software Substitute, which denies you control over your computing. Another meaning is renting a remote physical server, or virtual server.
These practices are ok under certain circumstances.