Dissecting Gargeband Effect

[UnlikeKurt]

Hello
Garageband has an effect called "Helium"
I would like to recreate this effect but without the use of garageband. Yes I realize I could import an audio file into garageband apply the effect and then fly it into whatever medium I am working in.
However, I am interested in understanding what it is doing and how to recreate it otb.
My ears are telling me its some sort of pitch shift with reverb but it also has something else going on that I cannot really figure out.

If anyone can chime in with some pointers it would be appreciated.

Thanks
James