Access from mobile application using SSO

I have a mobile app for sales. From the app, I want to go in ERPNext CRM Module. For this, I plan to create a button in the app named CRM. On click the button, ERPNext’s CRM mobule will open in mobile’s browser. I dont want user’s have to log-in again. In that case, I think I need same user’s in both appliction and other authentication way like Single Sign-On (SSO).

How can I implement this?