Smartphone filmmakers can order a small anamorphic optics for a trendy look -- including the horizontal flares -- on kickstarter until April 20. It offers a 1.33x horizontal "squeezing" during recording, which results in an aspect ratio of 2.40:1 cinemascope after the subsequent de-squeeze, and is mounted in front of the already integrated lens, for which a small housing with corresponding mount is additionally required. This can also be purchased on Kickstarter for iPhone X, for other models -- including pixels and Galaxy smartphones -- the manufacturer Moment offers corresponding cases on its website. If you already own older lenses and a smartphone case from Moment: they are not necessarily compatible.
The anamorphic optics itself costs approx. 100 Euro plus customs and dispatch; the very cheapest and earliest order variants are already out of stock. The project enjoys a sensational popularity -- instead of the original financing target of approx. 40,000 dollars, orders worth almost one million (!) have already been received. Also a filter mount and a gimbal counterweight can be ordered.
By the way, Steven Soderbergh is said to have used lenses from Moment the iPhone recordings for "Unsane" (the regular, not the new anamorphic).