Auto Login User Using Link

Hello
I need to know if it’s possible to auto login a user somehow using a custom link.
So they would click something like http://www.websiteaddress.co.uk/profile/username=username&password=password and they would then be logged into their profile or a page? I basically want a special redirection url - but only when this custom link is used, not for all users of the site?
I’m going to be linking to the website from an app, so the login information will be submitted in the app, but then this link would send them to their logged in profile page on the website.
Is this possible? Any advice much appreciated.
Thanks

@claschyt: The short answer is yes. The longer answer is that, despite appearances, s2Member does not handle logging in at all. It just leaves that to WordPress.

So the good news is that, if you can find a way of hooking your app into WP’s logging-in process, it should work with s2Member.

Ok great - thanks - anyone point me in the right direction of how to do this?

Just use the search term login app on the plugins section of wordpress.org and you’ll get a lot of options.