Issue 1:
have been geting use cases that requires either of those, but Haven't found how any of that can be implemented yet.

Who else sees a need for those features?

Issue 2:
Steps to Reproduce

On a mac with an iOS simulator open, execute

cd examples/layers
flutter run -t widgets/hello_world.dart

The build fails (log below). It appears that pod install was not done as part of building (cc @jakobr-google )

Works fine on the same host machine with an Android emulator open instead of the iOS simulator.

Logs

$ flutter run -t widgets/hello_world.dart
Launching widgets/hello_world.dart on iPhone 7 in debug mode...
Running Xcode build... 0.8s
Failed to build iOS app
Error output from Xcode build:
↳
** BUILD FAILED **

The following build commands failed:
PhaseScriptExecution [CP]\ Check\ Pods\ Manifest.lock /Users/mravn/Library/Developer/Xcode/DerivedData/Runner-fhkkylgwmjuozlesoxkkfccsachc/Build/Intermediates/Runner.build/Release-iphonesimulator/Runner.build/Script-AB1344B0443C71CD721E1BB7.sh
(1 failure)
Xcode's output:
↳
Build settings from command line:
ARCHS = x86_64
BUILD_DIR = /Users/mravn/github/flutter/examples/layers/build/ios
ONLY_ACTIVE_ARCH = YES
SDKROOT = iphonesimulator10.3

=== CLEAN TARGET Runner OF PROJECT Runner WITH CONFIGURATION Release ===

Check dependencies
Release.xcconfig line 2: Unable to find included file "Pods/Target Support Files/Pods-Runner/Pods-Runner.release.xcconfig"
Release.xcconfig line 2: Unable to find included file "Pods/Target Support Files/Pods-Runner/Pods-Runner.release.xcconfig"

Clean.Remove clean /Users/mravn/github/flutter/examples/layers/build/ios/Release-iphonesimulator/Runner.app
builtin-rm -rf /Users/mravn/github/flutter/examples/layers/build/ios/Release-iphonesimulator/Runner.app

Clean.Remove clean /Users/mravn/github/flutter/examples/layers/build/ios/Release-iphonesimulator/Runner.app.dSYM
builtin-rm -rf /Users/mravn/github/flutter/examples/layers/build/ios/Release-iphonesimulator/Runner.app.dSYM

Clean.Remove clean /Users/mravn/Library/Developer/Xcode/DerivedData/Runner-fhkkylgwmjuozlesoxkkfccsachc/Build/Intermediates/Runner.build/Release-iphonesimulator/Runner.build
builtin-rm -rf /Users/mravn/Library/Developer/Xcode/DerivedData/Runner-fhkkylgwmjuozlesoxkkfccsachc/Build/Intermediates/Runner.build/Release-iphonesimulator/Runner.build

** CLEAN SUCCEEDED **

=== BUILD TARGET Runner OF PROJECT Runner WITH CONFIGURATION Release ===

Check dependencies
Release.xcconfig line 2: Unable to find included file "Pods/Target Support Files/Pods-Runner/Pods-Runner.release.xcconfig"
Release.xcconfig line 2: Unable to find included file "Pods/Target Support Files/Pods-Runner/Pods-Runner.release.xcconfig"

Write auxiliary files
write-file /Users/mravn/Library/Developer/Xcode/DerivedData/Runner-fhkkylgwmjuozlesoxkkfccsachc/Build/Intermediates/Runner.build/Release-iphonesimulator/Runner.build/Script-AB1344B0443C71CD721E1BB7.sh
chmod 0755 /Users/mravn/Library/Developer/Xcode/DerivedData/Runner-fhkkylgwmjuozlesoxkkfccsachc/Build/Intermediates/Runner.build/Release-iphonesimulator/Runner.build/Script-AB1344B0443C71CD721E1BB7.sh
write-file /Users/mravn/Library/Developer/Xcode/DerivedData/Runner-fhkkylgwmjuozlesoxkkfccsachc/Build/Intermediates/Runner.build/Release-iphonesimulator/Runner.build/Runner-own-target-headers.hmap
write-file /Users/mravn/Library/Developer/Xcode/DerivedData/Runner-fhkkylgwmjuozlesoxkkfccsachc/Build/Intermediates/Runner.build/Release-iphonesimulator/Runner.build/Runner-project-headers.hmap
write-file /Users/mravn/Library/Developer/Xcode/DerivedData/Runner-fhkkylgwmjuozlesoxkkfccsachc/Build/Intermediates/Runner.build/Release-iphonesimulator/Runner.build/Script-95BB15E9E1769C0D146AA592.sh
chmod 0755 /Users/mravn/Library/Developer/Xcode/DerivedData/Runner-fhkkylgwmjuozlesoxkkfccsachc/Build/Intermediates/Runner.build/Release-iphonesimulator/Runner.build/Script-95BB15E9E1769C0D146AA592.sh
/bin/mkdir -p /Users/mravn/Library/Developer/Xcode/DerivedData/Runner-fhkkylgwmjuozlesoxkkfccsachc/Build/Intermediates/Runner.build/Release-iphonesimulator/Runner.build/Objects-normal/x86_64
write-file /Users/mravn/Library/Developer/Xcode/DerivedData/Runner-fhkkylgwmjuozlesoxkkfccsachc/Build/Intermediates/Runner.build/Release-iphonesimulator/Runner.build/Objects-normal/x86_64/Runner.LinkFileList
write-file /Users/mravn/Library/Developer/Xcode/DerivedData/Runner-fhkkylgwmjuozlesoxkkfccsachc/Build/Intermediates/Runner.build/Release-iphonesimulator/Runner.build/Runner.hmap
write-file /Users/mravn/Library/Developer/Xcode/DerivedData/Runner-fhkkylgwmjuozlesoxkkfccsachc/Build/Intermediates/Runner.build/Release-iphonesimulator/Runner.build/Script-9740EEB61CF901F6004384FC.sh
chmod 0755 /Users/mravn/Library/Developer/Xcode/DerivedData/Runner-fhkkylgwmjuozlesoxkkfccsachc/Build/Intermediates/Runner.build/Release-iphonesimulator/Runner.build/Script-9740EEB61CF901F6004384FC.sh
write-file /Users/mravn/Library/Developer/Xcode/DerivedData/Runner-fhkkylgwmjuozlesoxkkfccsachc/Build/Intermediates/Runner.build/Release-iphonesimulator/Runner.build/Script-532EA9D341340B1DCD08293D.sh
chmod 0755 /Users/mravn/Library/Developer/Xcode/DerivedData/Runner-fhkkylgwmjuozlesoxkkfccsachc/Build/Intermediates/Runner.build/Release-iphonesimulator/Runner.build/Script-532EA9D341340B1DCD08293D.sh
write-file /Users/mravn/Library/Developer/Xcode/DerivedData/Runner-fhkkylgwmjuozlesoxkkfccsachc/Build/Intermediates/Runner.build/Release-iphonesimulator/Runner.build/Script-3B06AD1E1E4923F5004D2608.sh
chmod 0755 /Users/mravn/Library/Developer/Xcode/DerivedData/Runner-fhkkylgwmjuozlesoxkkfccsachc/Build/Intermediates/Runner.build/Release-iphonesimulator/Runner.build/Script-3B06AD1E1E4923F5004D2608.sh
write-file /Users/mravn/Library/Developer/Xcode/DerivedData/Runner-fhkkylgwmjuozlesoxkkfccsachc/Build/Intermediates/Runner.build/Release-iphonesimulator/Runner.build/Runner-all-non-framework-target-headers.hmap
write-file /Users/mravn/Library/Developer/Xcode/DerivedData/Runner-fhkkylgwmjuozlesoxkkfccsachc/Build/Intermediates/Runner.build/Release-iphonesimulator/Runner.build/Runner-all-target-headers.hmap
write-file /Users/mravn/Library/Developer/Xcode/DerivedData/Runner-fhkkylgwmjuozlesoxkkfccsachc/Build/Intermediates/Runner.build/Release-iphonesimulator/Runner.build/Runner-generated-files.hmap

Create product structure
/bin/mkdir -p /Users/mravn/github/flutter/examples/layers/build/ios/Release-iphonesimulator/Runner.app

ProcessProductPackaging "" /Users/mravn/Library/Developer/Xcode/DerivedData/Runner-fhkkylgwmjuozlesoxkkfccsachc/Build/Intermediates/Runner.build/Release-iphonesimulator/Runner.build/Runner.app.xcent
cd /Users/mravn/github/flutter/examples/layers/ios
export PATH="/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/usr/bin:/Applications/Xcode.app/Contents/Developer/usr/bin:/Users/mravn/.rvm/gems/ruby-2.2.2/bin:/Users/mravn/.rvm/gems/ruby-2.2.2@global/bin:/Users/mravn/.rvm/rubies/ruby-2.2.2/bin:/usr/local/share/npm/bin:/Users/mravn/.pub-cache/bin:/Users/mravn/github/engine/src/third_party/android_tools/sdk/platform-tools:/Users/mravn/github/flutter/bin:/Users/mravn/tools/depot_tools:/Users/mravn/bin:/usr/local/git/current/bin:/usr/local/bin:/usr/bin:/bin:/usr/local/sbin:/usr/sbin:/sbin:/usr/local/go/bin:/Users/mravn/.rvm/bin"

Entitlements:

{
"application-identifier" = "AQ7UHDBEXJ.io.flutter.examples.Layers";
"keychain-access-groups" = (
"AQ7UHDBEXJ.io.flutter.examples.Layers"
);
}

builtin-productPackagingUtility -entitlements -format xml -o /Users/mravn/Library/Developer/Xcode/DerivedData/Runner-fhkkylgwmjuozlesoxkkfccsachc/Build/Intermediates/Runner.build/Release-iphonesimulator/Runner.build/Runner.app.xcent

PhaseScriptExecution [CP]\ Check\ Pods\ Manifest.lock /Users/mravn/Library/Developer/Xcode/DerivedData/Runner-fhkkylgwmjuozlesoxkkfccsachc/Build/Intermediates/Runner.build/Release-iphonesimulator/Runner.build/Script-AB1344B0443C71CD721E1BB7.sh
cd /Users/mravn/github/flutter/examples/layers/ios
/bin/sh -c /Users/mravn/Library/Developer/Xcode/DerivedData/Runner-fhkkylgwmjuozlesoxkkfccsachc/Build/Intermediates/Runner.build/Release-iphonesimulator/Runner.build/Script-AB1344B0443C71CD721E1BB7.sh
diff: /../Podfile.lock: No such file or directory
diff: /Manifest.lock: No such file or directory
error: The sandbox is not in sync with the Podfile.lock. Run 'pod install' or update your CocoaPods installation.

Could not build the application for the simulator.
Error launching application on iPhone 7.

Flutter Doctor

[✓] Flutter (on Mac OS X 10.12.4 16E195, channel master)
• Flutter at /Users/mravn/github/flutter
• Framework revision 9d3fb1f309 (15 hours ago), 2017-05-18 11:26:43 -0700
• Engine revision 82815836eb
• Tools Dart version 1.23.0-dev.11.11

[✓] Android toolchain - develop for Android devices (Android SDK 25.0.3)
• Android SDK at /Users/mravn/Library/Android/sdk
• Platform android-25, build-tools 25.0.3
• Java binary at: /Applications/Android Studio.app/Contents/jre/jdk/Contents/Home/bin/java
• Java version: OpenJDK Runtime Environment (build 1.8.0_112-release-b06)

[✓] iOS toolchain - develop for iOS devices (Xcode 8.3.2)
• Xcode at /Applications/Xcode.app/Contents/Developer
• Xcode 8.3.2, Build version 8E2002
• ios-deploy 1.9.1
• CocoaPods version 1.2.1

[✓] Android Studio (version 2.3)
• Android Studio at /Applications/Android Studio.app/Contents
• Gradle version 3.2
• Java version: OpenJDK Runtime Environment (build 1.8.0_112-release-b06)

[✓] IntelliJ IDEA Community Edition (version 2016.3.4)
• Dart plugin version 163.13137
• Flutter plugin version 12.0

[✓] WebStorm (version 2017.1.1)
• Flutter plugin version 13.0

[✓] Connected devices
• iPhone 7 • 61761BAD-7CA3-4A75-BFBA-39CA8D573E25 • ios • iOS 10.3 (simulator)