I've just released version 7 of Hot Potatoes, seven years after the last update.
The new version, which you can get from the HotPot site:
has a number of improvments, including a change to HTML5 output pages, support for drag-drop exercises on touch devices, ability to include reading texts with drag-drop exercises, and many more minor changes. You can install and use version 7 alongside version 6.
All the best,
University of Victoria, BC