For this tag to be distinct from mind control you need to specify the ways in which it differs from mind control, such as the pendulum gimmick, subconscious elements or the slow relaxing voice
In practice, it’s hentai, so there will be story where the character uses hypnosis, but artist cut off the details.
Resistance can also came in play in other type of mind control such as using magic when the effect weakens.
On the issue of “hypnosis apps”, I think the trope/fetish is established enough to get its own specific tag.
Completely agree. Would describe it as "The act of tempering with one's mind, compelling them to act or think in a certain way, even if would against their will otherwise, without giving them chance to resist."
Mind control is more like "The act of simultaneously controlling a third party's action, even against their will or against their mental resistance".
For some people, the induction is as arousing as the end result, if not more. Having a tag that could separate those works out from the works with instant mind control apps or the like would be useful. For example, the multi-work that starts with ##612842|Saimin, Kakete Mite | Hypnosis, Give it…|1,327.
after thinking about it for a while I have to agree with @hollowilds. The thing is that hypnosis has the extra step of putting the target in a trance-like state. I think it's enough of a difference to warrant making a separate tag