Hi,
The pages with a higher need of improvements are: Simulator and Stimulus.
One of the issues here is the color contrast and text-size for input fields, but possibly also arrangement of fields on pages with many inputs.
PS: I put this answer here, to raise the topic with the larger community: what GUI elements you see as most problematic?
But I strongly suggest that GSOC Project specific questions are written on the official INCF channel [1] or on our dedicated Skype group [2] not to bother everybody here with task specific explanations.