Geforce Now can be activated free of charge at Nvidia Shield devices. Nvidia seems to be making some changes to the service in the upcoming months and has decided to remove the $7.99 subscription for now.
https://www.nvidia.com/en-us/shie…force-now/
In your Shield, go to Games, Geforce Now and Join. The following titles can be played free of charge:
https://www.nvidia.com/en-us/shie…s/#library