Save login state in wordpress website using webview

Hi…
I made an app which is using webview to show a wordpress website.
Since user need to log in to use some of its feature… How to save the login information so that user don’t need to enter login credential every time they start the app?
I’m not understand coding such as php or get and post, cookies, etc…
Please kindly share how to do it…
Thank you vey much…