Stim.io natively supports both Xbox (Bluetooth) and PlayStation (Bluetooth) controllers but does not support other USB devices as this would require a native client and Stim.io is currently web based.
While we are working on native apps/clients, a workaround is to use something like https://www.virtualhere.com/ or https://www.flexihub.com/ which you can install to both your CloudPC, and on your local device. This allows you to redirect USB devices from your local device to your CloudPC.
We still recommend using the built-in Stim.io controller support for gamepads, but https://www.virtualhere.com/ & https://www.flexihub.com/ is a great workaround until the Stim.io native apps and clients are released. Both https://www.virtualhere.com/ & https://www.flexihub.com/ support USB microphones as well.
Our customers report that while Flexihub offers a 30-day trial, VirtualHere continues working after the trial without payment in a freemium fashion.
Note: Please contact their customer support for any issues with USB or Microphone support with 3rd party software such as VirtualHere or FlexiHub.