Unfortunately, the chances of a non-XenForo add-on being made available here at XenForo.com are incredibly slim.
I personally hate Tapatalk and even though it's installed on a lot of forums I visit, I never use it. I often prefer navigating the site on my phone on the default style.
I do see the appeal, though. I think the only way it will happen is if XenForo bundle it as a core add-on or feature.
Something tells me the won't strike up a deal with Forum Runner any time soon...