ProTube is an amazing YouTube app, I can't even think of watching YouTube videos on my iPhone without it. Developed by Jonas Gessner, this app already packs some amazing features so when he contacted me about testing this update the answer was already yes. This update adds the ability to stream 4k videos at 60fps, which to my knowledge isn't possible on iOS yet. Most notably iPhones don't automatically support 4k video out of the box. Or do they? According to Cult of Mac it's actually possible to sort of side-load 4k on an iPhone with an app called WALTR.
Apple packed the biggest display it’s ever made onto the iPhone 6 Plus, and while its 1920×1080 resolution is great for streaming 1080p videos, it turns out that Apple also secretly added 4K video support without telling anyone.
The iPad Air 2, iPhone 6 and iPhone 6 Plus all support 4K video playback out of the box, thanks to the new A8 processor added this year. Apple doesn’t list 4K video playback as one of the A8 chips features, but the discovery was made by the developers behind WALTR, who posted proof of 4K video playback on the iPhone 6 this weekend.
So, in theory the iPhone 6 and iPad Air 2 are capable of 4k. When I searched '4k video' after I started testing this update I was stunned at the quality I found. There isn't all that much in terms of content on YouTube in 4k yet, mostly nature shows but it was as though I was peering through a frame of reality and looking at real life moments. There's also the possibility of mirroring/displaying your iPhone or iPad to an external monitor with an Apple TV or the Lightning to HDMI Adapter. Gessner is also adding some addition features into the app; including replying to comments, setting the default playback quality on WiFi versus Cellular, and YouTubes new volume HUD which replaces the obnoxious stock iOS version which blocks about one-eight of your screen. ProTube is $2.99 in the App Store and is worth every cent. Check it out today if you want to get the most out of YouTube on iOS. This update should be out sometime after iOS 10 GM is released to the public.