Does Genymotion offer unlimited access for a single device?

✅ YES, the unlimited plan is billed per virtual device, so one device can be covered by that plan. For desktop licenses, one license can be used on one device plus one spare, which means 2 activations total, not unlimited devices. See Genymotion in the Cloud with a user-friendly interface and I get the error: "You have activated the maximum number of workstations allowed by your license".

Are you asking about a cloud subscription or a Desktop license?