Given how far smartphones have come, it was only a matter of time before directors started getting creative with them. That's part of the hook behind Unsane, a psychological thriller shot entirely on an iPhone 7 Plus.

It's not a stock iPhone, with director Steven Soderbergh using three special lenses and the standard iPhone lens. But Unsane was captivating enough that I forgot to keep looking for the visual differences - although there are some unmistakable scenes that the iPhone can't quite handle.