After going through some evaluation and hearing back from folks on sizing, I have decided to offer a third size of Koala Clip: X-LARGE.
If you use Lifeproof or Otterbox cases on your phone, it is making your phone too long for the size of Koala Clip based off phone model.
So if you use one of those two cases - please order up a size. So Iphone X with Otterbox - order a LARGE; Galaxy S9+ with Lifeproof case order an X-Large
Koala Clip is available in three sizes: Medium, Large, and X-Large sized specifically for phones and cases available on the market now.