I installed the data.com assessment app but Trailhead won't recognize it. 


Here is the challenge:

Install the Data.com Assessment App
Your VP of sales wants a 360-degree view of all the company’s accounts. Before you provide any reports, you want to assess the quality of your data. Install the Data.com Assessment App from the AppExchange, and review the results to determine the quality of the data.
Install the Data.com Assessment App into your Developer Edition, following the instructions provided in this unit.