It works with Kindle Fire because there is a App for it. When the Playbook gets update maybe you can used the Android App version to work with it. I do have it on my other devices but already had the Wi-Drive app on my Fire since it has been rooted from day one. I would love for it to work for the Playbook as well since I do carry the Wi-Drive with me.
Works with my PB. No app needed. Just point the browser to it, it has it's own built in interface. To make it easier I have a shortcut to it.
Just to be clear, it is the Wi-Drive that works with your PB? Do you have to be within range of some other wifi, or can you be in the middle of nowhere without wifi and still connect with it?