can you do a touchscreen left hand only keyboard?

My wife has had a stroke resulting in loss of use of her right hand.

I have been shown PC keyboards for left hand only, with shift keys

to provide, as an alternative to the left side of the keyboard,

1) the right side of the keyboard. 2) the number pad, 3) the function keys.

This type of stroke is pretty frequent. How hard would it be for you to

do an app for the iPad of this kind? My wife's speech therapist and I

think this would be very good for her morale, and it would mean we

could do all we'd like to on the one portable device. I think it would

sell very well, given the prevalence of this type of stroke. Thank you

for considering this.