Contradiction in fields added in Mobile-express form and in mobile application

I installed following mobile app for dynamics crm online. But I am seeing there are some issues regarding what fields I added on mobile-express form for Opportunity and what I am experiencing in mobile app. Also, the save button is set to disabled while creating new Opportunity. I filled all the required fields but Save button is still disabled. 

Any idea what I am missing?

https://play.google.com/store/apps/details?id=com.microsoft.crm.crmphone