In my first job out of college, I worked for Logica, and was involved in writing an application that plotted lightning strikes. The Met Office in the UK had a feed over a modem that provided lightning strike locations, and this application would plot them on a map of the UK, allowing the user to zoom in, and see the exact location. This app was aimed at Electric Companies to help them find downed power lines.
The first version was built using Windows 1.x (don't remember the value of x). I do remember that it did not support overlapping Windows - I think that was due to litigation with Apple.
Relatedly, I really like this article about the Skunk Works project that made Windows 3.0 run programs in protected mode.