Is this a bug report?

Yes, sort of, anyway something we should clarify

Have you read the Contributing Guidelines?

Yes

Environment

1. react-native -v:
   react-native-cli: 1.2.0
   react-native: 0.46.4

2. node -v:
   v6.9.1

3. npm -v:
   4.0.5

Then, specify:

• Target Platform:
  iOS

• Development Operating System:
  macOS Sierra 10.12.6

• Build tools:
  Xcode

Steps to Reproduce

(Write your steps here:)

1. Create a simple app with fixed font, something like

https://snack.expo.io/ry7LNPVv-

Expected Behavior

the font should be fixed

Actual Behavior

the font is bigger than expected

http://imgur.com/a/BxwWW

http://imgur.com/a/BxwWW

I know the problem is caused by setting Zoom in iphone Plus family by setting Display Zoom settings to "Zoomed" instead of "Standard"

Reproducible Demo

https://snack.expo.io/ry7LNPVv-

But i used react-native init on a fresh new project

Thanks.

Victor