One of the reasons I love my Apple Watch so much is having the ability to glance at my wrist to see information from Complications. On the other hand, I spend most of my time using  my iPhone as opposed to my Apple Watch, and it’d be nice to have watchOS-like Complications present on my iOS devices.
If you’re thinking along the same lines I am, then you might be interested in a newly released jailbreak tweak called Watermelon by iOS developer LaughingQuoll.