I'm working on a custom CYOA, in which you design your own Hypno-App, like what's seen fairly often in hentai, and I wanted to ask if there are any specific features that might be fun to ahve as options in the CYOA.

Currently, I'm not too far into the process, but I've got it so that you can purchase eight different hypnosis types: The standard spiral, subliminal audio, hypnotic body parts, pheromone production, a hypno-ray, a transformation ray, drone-ification, and a mass common sense changer. They aren't all balanced in terms of power, but the stronger ones of course cost more points to select, limiting the other features you can purchase.

I'd love to hear other people's ideas on more types of hypnosis, other miscellaneous perks one could choose, or drawbacks that could be selected to increase your point count. Obviously no promises I'll use anyone's ideas, but when the CYOA is finished, I'll post it in this thread.

I would be interested in an a bodycontrol mode, like an external device connected to the app (like a tech collar for example).
Since a bodycontrol device has as the name implies not full control, that could be one of the drawbacks of this type but since this kind of control doesnt actually target the mind but instead targets the motor systems of the body directly it can overcome other kinds of control and mostly ignores willpower and mental resistance.

I remember one erotic manga i read where the app could install personalities and it wouldn't be a CYOA without draw backs Like it can only work on one person at a time or you need use it on one persona multiple times for it to stick

There are quite a lot of existing mind control CYOAs, you could look at those for inspiration.

A variation on the mass common sense changer - a social media app that brainwashes users into having a super slutty online presence. So instead of being a free-use thing you have a bunch of blackmail material. This would almost certainly be a cheap-o option.

There's also the idea of making it a "dating" app, kinda like #173738.