Does any cloud service provide free GPU access? Is there any cloud developer platform which provides free access to an NVIDIA GPU instance, maybe only for a limited trial period? I'd like to work on it before committing to a paid option. I have tried AWS, Google Cloud Developer Platform and IBM Bluemix, but none of them have this option.
Nvidia has it's own online labs where they can help you learn GPU based data processing. Might be worth checking out for you if you want to learn and play around within the online lab environment.

https://developer.nvidia.com/dli/onlinelabs

All the best.