why did I find this when I put nsfw and mind control into the tag thing?
Because those are two of the tags this program has.
While it does not have any explicit NSFW content it is specifically targeted at that market, and likewise while it cannot on its own control a mind, that is is both the goal and dream.
I'm not understanding exactly what the nsfw part of the hypnosis app is
The target market is the NSFW aspect. Though if you were to sit at your desk at work and openly bliss out to spirals that is your choice.
