I can't reach the top left corner on my Galaxy S3 or Nexus 4 so I don't put any apps there. The keyboard when revealed is near the bottom of the phone where I can reach all characters with my thumb if needed. It seems to me that all those claiming that a device is not useable one handed think that all its functions are crammed into the top left corner, I agree there is difficulty with the larger phones but not nearly as difficult as some make out.
I prefer using two hands BTW.
I prefer using two hands BTW.