Answers for "how to run react native project in ios simulator"

react native run ios runing the app in simulator not in Iphone

react-native run-ios --device

this is for connected devices


react-native run-ios --simulator="simulator name"

or 

react-native run-ios --simulator

how to run react native app on simulator

react-native run-ios

it choose the simulator automatically 

react-native run-android 

for already open android emulator