So I clicked on the link in your post in safari on Sierra, and it's literally a blank page. I was curious so I opened the developer console and it says:
"app.initialize is not a function (in app.initialize({"api":"https:\/\/api.visualtip.com","key":"db4430ab8da22455511f9b26963a7151835ef5471b82"});"
I haven't the slightest idea what that means, but would have expected to at least see some sort of header or un-styled text rather than absolutely nothing!