Keep android application always in logged in state in C#.Net

I am trying to create a mobile web app using c# and create apk with appsgeyser. My issue is i have to keep my user logged in.

When a user login to the app using userid and password, after he closes and reopens the app he must stay logged in. (*login directly to the system without giving userid/password when user reopens the app.)

I tried cookies,session but nothing worked.

Is there any way to save the login userid and reuse.