The medical industry needs (good) software that helps with diagnosis. This covers mental health also.
You have symptoms of problem and it helps narrow down. Need a massive database of all known diseases as well as symptoms / remedies. Chart location data for origin of specific disease, (less likely to be rabies if Australia etc) and probability from all factors.
Would require huge amounts of data as well as many man hours to create but a system that does this task would be one of most beneficial medical breakthrough possible right now in my eyes.
Especially in mental health where there are symptoms of many things over many separate disorder, or rare one. It would be a bonus if you could let this information to be fully public, especially if one could direct users to relevant places.