CRM mobile express app not connecting to CRM server

Hi everyone,

I setup ADFS on a Windows 2008R2 server and IFD on a Windows 2012R2 server that is running CRM 2015.  I can access CRM from inside and outside the network without any problem.  I can access CRM from the phone as well as long as I use a browser instead of the app.  When I try to connect using the app, I get a white screen with an arrow on top to return to the previous page where you enter the URL for the CRM server.  I don't get a prompt for username or password.  I examined the event logs on both servers and I don't see any errors.

Any suggestions of how to troubleshoot this issue?

Thanks

Mario