You can view the Total Workflows by Category gadget on the Connectors Usage Page.

The Total Workflows by Category gadget displays the total number of workflows that use a specific connector for the selected time frame by category (PTC Apps and Unclassified).

Hover the cursor over the graph to see the exact number of workflows by category that use a particular connector in the selected time frame. If you do not see a value for a particular legend, consider its value as 0.