We have deployed the ComponentSpace SAML Identity Provider Library on IIS. When we initiate SSO from a desktop browser, SSO is working fine. From a iOS mobile device, when you install the Google Drive Mobile app and enter your email address (where the domain is federated by Google), you click next button and it just hangs. Nothing pops up and there is no response. I’ve open a ticket with Google eSupport and they could not provide any meaningful feedback. I was told that this may be due to Application Transport Security requirements on iOS. Has anyone encountered this issue? 
Hopefully Google or Apple will provide a fix.
If anyone is aware of a workaround or fix please reply to this post.