Thanks for getting back to me! So as far as I can tell switch controllers (Pro & Joy-con) don't support vibration outside of the switch through Unity. So they will work like any other controller, just vibration will not. The 360 controller should be working however, but only through a USB connection. Unfortunately at this stage wireless isn't supported.
Viewing post in iVIBRATE Ultimate Edition comments
That's really strange, there is no reason for the 360 controller through USB to not work. Are you on Windows 10? I have heard of people having problems on operating systems such as Windows 7.
In saying that, there is a new update coming out soon that completely replaces the input system of this app and should hopefully fix a lot of these issues that you and others are having too!