Hello,

as much as I wait for a keyboard-OTH and I'm delighted on your initiative, I'm not sure about your current design.

I'm a log term user of mobile devices with keyboard (Psion 5, Psion Revo, Nokia E71, Nokia E7)
From your design image and my experience I discover a lot of wasted space. Also the D-Pad is not really a good investment on space, as we have an brilliant touch screen.
Instead of that huge frame I'd prefer a dedicated row for numbers and extra special keys such as arrows, braces and dedicated punctuation.

On my E7 which is a similar form factor I always used my thumbs for typing. The D-Pad on the right makes it harder for the right thumb to reach the keys.

I'm not aware of any better keyboard. Well the Psion5 Keyboards were great which I even used with touch typing, even the Psion Revo, which is closer to the Jolla form factor was not bad.

However size is not the only matter. The keyboard on my old E71 (Blackberry Formfactor) the tiny keyboard was excellent and I was quicker on that than on the much bigger E7.

Sorry for my destructive comments, I'm just worried that you will spend a lot of work and money and in the end you may be disappointed with the usability.

cheers Jo