Podfile

source 'https://github.com/CocoaPods/Specs.git'
platform :ios, '9.0'

target 'YOUR_PROJECT_NAME' do
  pod 'ExpoKit',
    :git => "http://github.com/expo/expo.git",
    :tag => "ios/2.7.0",
    :subspecs => [
      "Core"
    ],
    :inhibit_warnings => true
  pod 'EXGL',
    :path => "../node_modules/expo/node_modules/expo-gl/ios",
    :inhibit_warnings => true
  pod 'EXCore',
    :path => "../node_modules/expo/node_modules/expo-core/ios",
    :inhibit_warnings => true
  pod 'EXCamera',
    :path => "../node_modules/expo/node_modules/expo-camera/ios",
    :inhibit_warnings => true
  pod 'EXSensors',
    :path => "../node_modules/expo/node_modules/expo-sensors/ios",
    :inhibit_warnings => true
  pod 'EXConstants',
    :path => "../node_modules/expo/node_modules/expo-constants/ios",
    :inhibit_warnings => true
  pod 'EXFileSystem',
    :path => "../node_modules/expo/node_modules/expo-file-system/ios",
    :inhibit_warnings => true
  pod 'EXPermissions',
    :path => "../node_modules/expo/node_modules/expo-permissions/ios",
    :inhibit_warnings => true
  pod 'EXCameraInterface',
    :path => "../node_modules/expo/node_modules/expo-camera-interface/ios",
    :inhibit_warnings => true
  pod 'EXSensorsInterface',
    :path => "../node_modules/expo/node_modules/expo-sensors-interface/ios",
    :inhibit_warnings => true
  pod 'EXConstantsInterface',
    :path => "../node_modules/expo/node_modules/expo-constants-interface/ios",
    :inhibit_warnings => true
  pod 'EXReactNativeAdapter',
    :path => "../node_modules/expo/node_modules/expo-react-native-adapter/ios",
    :inhibit_warnings => true
  pod 'EXFileSystemInterface',
    :path => "../node_modules/expo/node_modules/expo-file-system-interface/ios",
    :inhibit_warnings => true
  pod 'EXPermissionsInterface',
    :path => "../node_modules/expo/node_modules/expo-permissions-interface/ios",
    :inhibit_warnings => true
  pod 'EXFaceDetectorInterface',
    :path => "../node_modules/expo/node_modules/expo-face-detector-interface/ios",
    :inhibit_warnings => true
  pod 'EXSMS',
    :path => "../node_modules/expo/node_modules/expo-sms/ios",
    :inhibit_warnings => true
  pod 'EXGL-CPP',
    :path => "../node_modules/expo/node_modules/expo-gl-cpp/cpp",
    :inhibit_warnings => true

  pod 'React',
    :path => "../node_modules/react-native",
    :inhibit_warnings => true,
    :subspecs => [
      "Core",
      "ART",
      "RCTActionSheet",
      "RCTAnimation",
      "RCTCameraRoll",
      "RCTGeolocation",
      "RCTImage",
      "RCTNetwork",
      "RCTText",
      "RCTVibration",
      "RCTWebSocket",
      "DevSupport",
      "CxxBridge"
    ]
  pod 'yoga',
    :path => "../node_modules/react-native/ReactCommon/yoga",
    :inhibit_warnings => true
  pod 'DoubleConversion',
    :podspec => "../node_modules/react-native/third-party-podspecs/DoubleConversion.podspec",
    :inhibit_warnings => true
  pod 'Folly',
    :podspec => "../node_modules/react-native/third-party-podspecs/Folly.podspec",
    :inhibit_warnings => true
  pod 'glog',
    :podspec => "../node_modules/react-native/third-party-podspecs/glog.podspec",
    :inhibit_warnings => true


  post_install do |installer|
    installer.pods_project.main_group.tab_width = '2';
    installer.pods_project.main_group.indent_width = '2';

    installer.pod_targets.each do |target|

    if target.pod_name == 'ExpoKit'
      target.native_target.build_configurations.each do |config|
        config.build_settings['GCC_PREPROCESSOR_DEFINITIONS'] ||= ['$(inherited)']
        config.build_settings['GCC_PREPROCESSOR_DEFINITIONS'] << 'EX_DETACHED=1'
        
        # needed for GoogleMaps 2.x
        config.build_settings['FRAMEWORK_SEARCH_PATHS'] ||= []
        config.build_settings['FRAMEWORK_SEARCH_PATHS'] << '${PODS_ROOT}/GoogleMaps/Base/Frameworks'
        config.build_settings['FRAMEWORK_SEARCH_PATHS'] << '${PODS_ROOT}/GoogleMaps/Maps/Frameworks'
      end
    end


    if ['Amplitude-iOS','Analytics','AppAuth','Branch','CocoaLumberjack','FBSDKCoreKit','FBSDKLoginKit','FBSDKShareKit','GPUImage','JKBigInteger2'].include? target.pod_name
      target.native_target.build_configurations.each do |config|
        config.build_settings['IPHONEOS_DEPLOYMENT_TARGET'] = '9.0'
      end
    end
    # Can't specify this in the React podspec because we need
    # to use those podspecs for detached projects which don't reference ExponentCPP.
    if target.pod_name.start_with?('React')
      target.native_target.build_configurations.each do |config|
        config.build_settings['IPHONEOS_DEPLOYMENT_TARGET'] = '9.0'
        config.build_settings['HEADER_SEARCH_PATHS'] ||= ['$(inherited)']
      end
    end
    # Build React Native with RCT_DEV enabled
    next unless target.pod_name == 'React'
    target.native_target.build_configurations.each do |config|
      config.build_settings['GCC_PREPROCESSOR_DEFINITIONS'] ||= ['$(inherited)']
      config.build_settings['GCC_PREPROCESSOR_DEFINITIONS'] << 'RCT_DEV=1'
    end

    end
  end
end

For reference to other people that might have issues, I had to change the paths from "../node_modules/expo/node_modules/" to "../node_modules/"

I had the same issue, where I had to change the node_modules paths to what @valentin7 did above, as all of these packages are in my top-level node_modules. Any idea why this is different? Just trying to make sure it will not be in one place on one developer's machine and another place on another's.

the same here, I'm using yarn maybe yarn places the files in different order?

I also had to add

  pod 'EXFaceDetector',
    :path => "../node_modules/expo-face-detector/ios",
    :inhibit_warnings => true

otherwise on startup I'd get errors. This is on a project which was ejected from 27 originally.