Tell HN: iCloud Mail web app has a new look

Probably many of you don't know this because you use the app on your iPhones. I don't iPhone, so I often log in to my iCloud via the web. Just noticed it has a new style. I think it's the only major overhaul for the last 3 or 4 years at least. I heard previously they build iCloud web apps using SproutCore. I wonder if this is still the case.