Interesting concept: http://www.alphaui.com/en/twiky-product/
Video here : http://www.alphaui.com/en/user-benefits/

It looks a lot than an enhanced Microwriter : http://en.wikipedia.org/wiki/Microwriter.

Not sure it would fit on a 4.5" Jolla and still be usable, as current version is for 7" tablet, and the hand size remains... but the idea still stands.

I wonder how is the speed of typing text with this and the learning curve ?