I have great difficulty in using touchscreens - somehow they just don't work at all well for my fingers. This applies to a range of manufactured products - PCs, Apple products, Kindles...
I touch or press my finger against the screen... nothing. Press again, lighter or harder... nothing: it doesn't know I am there.
Sometimes breathing on my fingertip seems to help; but generally I just have to repeat again and again until eventually something happens, but usually not what I wanted.
Perhaps it is that my fingers are just too blunt-ended - that I am digitally handicapped. Or maybe they are the wrong temperature (I have warm hands most of the time - but I would have thought that would be helpful, rather than a hindrance).
My keyboard typing is okay (three-fingered) but I do need reasonably large keys - normal sized keys. I cannot depress just one key on many hand held devices - I have to used a rubber-tipped 'wand' or stylus.
Whatever the cause, it seems I am stuck with it, and the age of portable digitally operated devices is a frustration rather than a pleasure.
Note: This blog post contains photos of my - seemingly - deformed hands: