Depends on the need of the client.
Currently I am writing an application to track people who get beaten and those who beat them. From the initial call all the way to getting an advocate assigned to a court hearing and beyond.
I have delved into the medical field, the automotive industry, manufacturing, online surveys, some automation (robotics, very little) and several small things in other areas.
I even wrote a sales forecasting app for a dog food company. That was different.