Adaptive Content Scaling

I was trying to follow this guide to adaptive content scaling. 
https://coronalabs.com/blog/2014/10/28/resolution-independence-adaptive-content-scaling-in-corona/

This is exactly what I need for my business app, but for some reason I am still getting letterboxing on my iPhone 6s. My config.lua look just like the example, and all of my images/layouts reference a content area of 320x460. Am I just missing something simple? Any help greatly appreciated.

Config.lua: --calculate the aspect ratio of the device local aspectRatio = display.pixelHeight / display.pixelWidth application = {     content = {         -- width = assumes 320         -- height = assumes 480         scale = "adaptive",         fps = 60,         imageSuffix = {             ["@2x"] = 1.5,             ["@3x"] = 2.5,         },     }, }

Turns out I needed to include the launch images. That seems to have taken care of the issue.

Turns out I needed to include the launch images. That seems to have taken care of the issue.