Is this app and websites like webmd worsening hypochondria?

Not at all!: Hypochondiasis is a fear of having, or the idea that one has, a serious disease based on the person's misinterpretation of bodily symptoms. Fears tend to increase in the absence of good information. So, websites like this one allow people to quickly get information on symptoms or health issues of interest. Consequently, they are less likely to have irrational fears of being sick.