Sorry, no other devices are currently supported by fTelnet. It's not that I don't want to port to iOS or Android, both of which should be fairly straightforward since they support running Adobe AIR applications (which is what the PlayBook version is), it's just that I don't have the hardware to test with!
So if you have some hardware you'd like to donate, then I'd be more than happy to port fTelnet to it (or at least try -- I can't guarantee anything). Otherwise, you'll have to wait for a good sale to come on that makes me want to buy a new device.
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(Please note that donations are not tax-deductible for income tax purposes.)
Or how about IOTA?