how to programally login to wordpress without writing php code

Hi there,
I’m new to wordpress, I just installed wordpress 4.8 ( downloaded from ww.wp.xz.cn) into my pc so I can play with it.
I’m trying to figure out a quicker way to login to wordpress programingly.
we have our own web application running on mobile device (like iphone, ipad ) and pc. We want to do is: from our application we will have a button, when user click button, we will have a popup window and take user to wordpress site so user can see documents in wordpress. Since user already logged into our application, we don’t want user to do another login to wordpress. We want wordpress login to be done via program.
I posted some questions related to oauth plugin and also the login via url, but it seems I need to do some programming to twist the site. I don’t know php and starting to learn it, so it will take me sometime to learn and figure out how to do it. (I’ll keep researching on this path).
In the meantime I want to ask is there any solution that I don’t have to do php programming, just by some configuration setup and maybe playing with url then I can do login part through program and let user see documents in wordpress in popup window? This can cut our integration time.

Thanks, Helen