Netflix has updated its iOS application with HDR support for newer devices, including the iPhone 8 and 8 Plus, as well as the forthcoming iPhone X. It also works on the iPad Pro 12.9 and 10.5 from 2017, if you happen to have one of those devices.
Netflix HDR streaming requires a premium subscription plan, as well as more recent hardware. Some of the newest Android phones have already offered HDR support, including the Samsung Galaxy Note 8 and the LG G6.
There’s some debate about whether or not you’ll get “true” HDR given the brightness limitations of Apple’s LCD panels, and it’s probably more than you need on a screen that small anyway, but it’s nice to have the option if you’re a regular consumer of streaming media.