diff --git a/154-xcconfig-files/ConfigDemo/ConfigDemo.xcodeproj/project.pbxproj b/154-xcconfig-files/ConfigDemo/ConfigDemo.xcodeproj/project.pbxproj
new file mode 100644
index 0000000..8078a6a
--- /dev/null
+++ b/154-xcconfig-files/ConfigDemo/ConfigDemo.xcodeproj/project.pbxproj
@@ -0,0 +1,254 @@
+// !$*UTF8*$!
+{
+	archiveVersion = 1;
+	classes = {
+	};
+	objectVersion = 46;
+	objects = {
+
+/* Begin PBXBuildFile section */
+		B59797AC1A74354B00F7D280 /* main.m in Sources */ = {isa = PBXBuildFile; fileRef = B59797AB1A74354B00F7D280 /* main.m */; };
+		B59797AF1A74354B00F7D280 /* AppDelegate.m in Sources */ = {isa = PBXBuildFile; fileRef = B59797AE1A74354B00F7D280 /* AppDelegate.m */; };
+		B59797B21A74354B00F7D280 /* ViewController.m in Sources */ = {isa = PBXBuildFile; fileRef = B59797B11A74354B00F7D280 /* ViewController.m */; };
+		B59797B51A74354B00F7D280 /* Main.storyboard in Resources */ = {isa = PBXBuildFile; fileRef = B59797B31A74354B00F7D280 /* Main.storyboard */; };
+		B59797B71A74354B00F7D280 /* Images.xcassets in Resources */ = {isa = PBXBuildFile; fileRef = B59797B61A74354B00F7D280 /* Images.xcassets */; };
+		B59797BA1A74354B00F7D280 /* LaunchScreen.xib in Resources */ = {isa = PBXBuildFile; fileRef = B59797B81A74354B00F7D280 /* LaunchScreen.xib */; };
+/* End PBXBuildFile section */
+
+/* Begin PBXFileReference section */
+		B59797A61A74354B00F7D280 /* ConfigDemo.app */ = {isa = PBXFileReference; explicitFileType = wrapper.application; includeInIndex = 0; path = ConfigDemo.app; sourceTree = BUILT_PRODUCTS_DIR; };
+		B59797AA1A74354B00F7D280 /* Info.plist */ = {isa = PBXFileReference; lastKnownFileType = text.plist.xml; path = Info.plist; sourceTree = "<group>"; };
+		B59797AB1A74354B00F7D280 /* main.m */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.objc; path = main.m; sourceTree = "<group>"; };
+		B59797AD1A74354B00F7D280 /* AppDelegate.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = AppDelegate.h; sourceTree = "<group>"; };
+		B59797AE1A74354B00F7D280 /* AppDelegate.m */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.objc; path = AppDelegate.m; sourceTree = "<group>"; };
+		B59797B01A74354B00F7D280 /* ViewController.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = ViewController.h; sourceTree = "<group>"; };
+		B59797B11A74354B00F7D280 /* ViewController.m */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.objc; path = ViewController.m; sourceTree = "<group>"; };
+		B59797B41A74354B00F7D280 /* Base */ = {isa = PBXFileReference; lastKnownFileType = file.storyboard; name = Base; path = Base.lproj/Main.storyboard; sourceTree = "<group>"; };
+		B59797B61A74354B00F7D280 /* Images.xcassets */ = {isa = PBXFileReference; lastKnownFileType = folder.assetcatalog; path = Images.xcassets; sourceTree = "<group>"; };
+		B59797B91A74354B00F7D280 /* Base */ = {isa = PBXFileReference; lastKnownFileType = file.xib; name = Base; path = Base.lproj/LaunchScreen.xib; sourceTree = "<group>"; };
+		B59797D01A7435C200F7D280 /* Application.xcconfig */ = {isa = PBXFileReference; lastKnownFileType = text.xcconfig; path = Application.xcconfig; sourceTree = "<group>"; };
+		B59797D11A7435CD00F7D280 /* Debug.xcconfig */ = {isa = PBXFileReference; lastKnownFileType = text.xcconfig; path = Debug.xcconfig; sourceTree = "<group>"; };
+		B59797D21A7435D300F7D280 /* Release.xcconfig */ = {isa = PBXFileReference; lastKnownFileType = text.xcconfig; path = Release.xcconfig; sourceTree = "<group>"; };
+		B59797D31A7435D800F7D280 /* Shared.xcconfig */ = {isa = PBXFileReference; lastKnownFileType = text.xcconfig; path = Shared.xcconfig; sourceTree = "<group>"; };
+/* End PBXFileReference section */
+
+/* Begin PBXFrameworksBuildPhase section */
+		B59797A31A74354B00F7D280 /* Frameworks */ = {
+			isa = PBXFrameworksBuildPhase;
+			buildActionMask = 2147483647;
+			files = (
+			);
+			runOnlyForDeploymentPostprocessing = 0;
+		};
+/* End PBXFrameworksBuildPhase section */
+
+/* Begin PBXGroup section */
+		B597979D1A74354B00F7D280 = {
+			isa = PBXGroup;
+			children = (
+				B59797A81A74354B00F7D280 /* ConfigDemo */,
+				B59797A71A74354B00F7D280 /* Products */,
+			);
+			sourceTree = "<group>";
+		};
+		B59797A71A74354B00F7D280 /* Products */ = {
+			isa = PBXGroup;
+			children = (
+				B59797A61A74354B00F7D280 /* ConfigDemo.app */,
+			);
+			name = Products;
+			sourceTree = "<group>";
+		};
+		B59797A81A74354B00F7D280 /* ConfigDemo */ = {
+			isa = PBXGroup;
+			children = (
+				B59797AD1A74354B00F7D280 /* AppDelegate.h */,
+				B59797AE1A74354B00F7D280 /* AppDelegate.m */,
+				B59797B01A74354B00F7D280 /* ViewController.h */,
+				B59797B11A74354B00F7D280 /* ViewController.m */,
+				B59797B31A74354B00F7D280 /* Main.storyboard */,
+				B59797B61A74354B00F7D280 /* Images.xcassets */,
+				B59797B81A74354B00F7D280 /* LaunchScreen.xib */,
+				B59797A91A74354B00F7D280 /* Supporting Files */,
+			);
+			path = ConfigDemo;
+			sourceTree = "<group>";
+		};
+		B59797A91A74354B00F7D280 /* Supporting Files */ = {
+			isa = PBXGroup;
+			children = (
+				B59797CF1A7435A400F7D280 /* Build Configuration */,
+				B59797AA1A74354B00F7D280 /* Info.plist */,
+				B59797AB1A74354B00F7D280 /* main.m */,
+			);
+			name = "Supporting Files";
+			sourceTree = "<group>";
+		};
+		B59797CF1A7435A400F7D280 /* Build Configuration */ = {
+			isa = PBXGroup;
+			children = (
+				B59797D01A7435C200F7D280 /* Application.xcconfig */,
+				B59797D11A7435CD00F7D280 /* Debug.xcconfig */,
+				B59797D21A7435D300F7D280 /* Release.xcconfig */,
+				B59797D31A7435D800F7D280 /* Shared.xcconfig */,
+			);
+			name = "Build Configuration";
+			sourceTree = "<group>";
+		};
+/* End PBXGroup section */
+
+/* Begin PBXNativeTarget section */
+		B59797A51A74354B00F7D280 /* ConfigDemo */ = {
+			isa = PBXNativeTarget;
+			buildConfigurationList = B59797C91A74354B00F7D280 /* Build configuration list for PBXNativeTarget "ConfigDemo" */;
+			buildPhases = (
+				B59797A21A74354B00F7D280 /* Sources */,
+				B59797A31A74354B00F7D280 /* Frameworks */,
+				B59797A41A74354B00F7D280 /* Resources */,
+			);
+			buildRules = (
+			);
+			dependencies = (
+			);
+			name = ConfigDemo;
+			productName = ConfigDemo;
+			productReference = B59797A61A74354B00F7D280 /* ConfigDemo.app */;
+			productType = "com.apple.product-type.application";
+		};
+/* End PBXNativeTarget section */
+
+/* Begin PBXProject section */
+		B597979E1A74354B00F7D280 /* Project object */ = {
+			isa = PBXProject;
+			attributes = {
+				LastUpgradeCheck = 0610;
+				ORGANIZATIONNAME = NSScreencast;
+				TargetAttributes = {
+					B59797A51A74354B00F7D280 = {
+						CreatedOnToolsVersion = 6.1.1;
+					};
+				};
+			};
+			buildConfigurationList = B59797A11A74354B00F7D280 /* Build configuration list for PBXProject "ConfigDemo" */;
+			compatibilityVersion = "Xcode 3.2";
+			developmentRegion = English;
+			hasScannedForEncodings = 0;
+			knownRegions = (
+				en,
+				Base,
+			);
+			mainGroup = B597979D1A74354B00F7D280;
+			productRefGroup = B59797A71A74354B00F7D280 /* Products */;
+			projectDirPath = "";
+			projectRoot = "";
+			targets = (
+				B59797A51A74354B00F7D280 /* ConfigDemo */,
+			);
+		};
+/* End PBXProject section */
+
+/* Begin PBXResourcesBuildPhase section */
+		B59797A41A74354B00F7D280 /* Resources */ = {
+			isa = PBXResourcesBuildPhase;
+			buildActionMask = 2147483647;
+			files = (
+				B59797B51A74354B00F7D280 /* Main.storyboard in Resources */,
+				B59797BA1A74354B00F7D280 /* LaunchScreen.xib in Resources */,
+				B59797B71A74354B00F7D280 /* Images.xcassets in Resources */,
+			);
+			runOnlyForDeploymentPostprocessing = 0;
+		};
+/* End PBXResourcesBuildPhase section */
+
+/* Begin PBXSourcesBuildPhase section */
+		B59797A21A74354B00F7D280 /* Sources */ = {
+			isa = PBXSourcesBuildPhase;
+			buildActionMask = 2147483647;
+			files = (
+				B59797B21A74354B00F7D280 /* ViewController.m in Sources */,
+				B59797AF1A74354B00F7D280 /* AppDelegate.m in Sources */,
+				B59797AC1A74354B00F7D280 /* main.m in Sources */,
+			);
+			runOnlyForDeploymentPostprocessing = 0;
+		};
+/* End PBXSourcesBuildPhase section */
+
+/* Begin PBXVariantGroup section */
+		B59797B31A74354B00F7D280 /* Main.storyboard */ = {
+			isa = PBXVariantGroup;
+			children = (
+				B59797B41A74354B00F7D280 /* Base */,
+			);
+			name = Main.storyboard;
+			sourceTree = "<group>";
+		};
+		B59797B81A74354B00F7D280 /* LaunchScreen.xib */ = {
+			isa = PBXVariantGroup;
+			children = (
+				B59797B91A74354B00F7D280 /* Base */,
+			);
+			name = LaunchScreen.xib;
+			sourceTree = "<group>";
+		};
+/* End PBXVariantGroup section */
+
+/* Begin XCBuildConfiguration section */
+		B59797C71A74354B00F7D280 /* Debug */ = {
+			isa = XCBuildConfiguration;
+			baseConfigurationReference = B59797D01A7435C200F7D280 /* Application.xcconfig */;
+			buildSettings = {
+			};
+			name = Debug;
+		};
+		B59797C81A74354B00F7D280 /* Release */ = {
+			isa = XCBuildConfiguration;
+			baseConfigurationReference = B59797D01A7435C200F7D280 /* Application.xcconfig */;
+			buildSettings = {
+			};
+			name = Release;
+		};
+		B59797CA1A74354B00F7D280 /* Debug */ = {
+			isa = XCBuildConfiguration;
+			baseConfigurationReference = B59797D11A7435CD00F7D280 /* Debug.xcconfig */;
+			buildSettings = {
+				INFOPLIST_FILE = ConfigDemo/Info.plist;
+				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks";
+				PRODUCT_NAME = "$(TARGET_NAME)";
+			};
+			name = Debug;
+		};
+		B59797CB1A74354B00F7D280 /* Release */ = {
+			isa = XCBuildConfiguration;
+			baseConfigurationReference = B59797D21A7435D300F7D280 /* Release.xcconfig */;
+			buildSettings = {
+				INFOPLIST_FILE = ConfigDemo/Info.plist;
+				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks";
+				PRODUCT_NAME = "$(TARGET_NAME)";
+			};
+			name = Release;
+		};
+/* End XCBuildConfiguration section */
+
+/* Begin XCConfigurationList section */
+		B59797A11A74354B00F7D280 /* Build configuration list for PBXProject "ConfigDemo" */ = {
+			isa = XCConfigurationList;
+			buildConfigurations = (
+				B59797C71A74354B00F7D280 /* Debug */,
+				B59797C81A74354B00F7D280 /* Release */,
+			);
+			defaultConfigurationIsVisible = 0;
+			defaultConfigurationName = Release;
+		};
+		B59797C91A74354B00F7D280 /* Build configuration list for PBXNativeTarget "ConfigDemo" */ = {
+			isa = XCConfigurationList;
+			buildConfigurations = (
+				B59797CA1A74354B00F7D280 /* Debug */,
+				B59797CB1A74354B00F7D280 /* Release */,
+			);
+			defaultConfigurationIsVisible = 0;
+			defaultConfigurationName = Release;
+		};
+/* End XCConfigurationList section */
+	};
+	rootObject = B597979E1A74354B00F7D280 /* Project object */;
+}
diff --git a/154-xcconfig-files/ConfigDemo/ConfigDemo/AppDelegate.h b/154-xcconfig-files/ConfigDemo/ConfigDemo/AppDelegate.h
new file mode 100644
index 0000000..e8d10df
--- /dev/null
+++ b/154-xcconfig-files/ConfigDemo/ConfigDemo/AppDelegate.h
@@ -0,0 +1,17 @@
+//
+//  AppDelegate.h
+//  ConfigDemo
+//
+//  Created by Ben Scheirman on 1/24/15.
+//  Copyright (c) 2015 NSScreencast. All rights reserved.
+//
+
+#import <UIKit/UIKit.h>
+
+@interface AppDelegate : UIResponder <UIApplicationDelegate>
+
+@property (strong, nonatomic) UIWindow *window;
+
+
+@end
+
diff --git a/154-xcconfig-files/ConfigDemo/ConfigDemo/AppDelegate.m b/154-xcconfig-files/ConfigDemo/ConfigDemo/AppDelegate.m
new file mode 100644
index 0000000..125354d
--- /dev/null
+++ b/154-xcconfig-files/ConfigDemo/ConfigDemo/AppDelegate.m
@@ -0,0 +1,45 @@
+//
+//  AppDelegate.m
+//  ConfigDemo
+//
+//  Created by Ben Scheirman on 1/24/15.
+//  Copyright (c) 2015 NSScreencast. All rights reserved.
+//
+
+#import "AppDelegate.h"
+
+@interface AppDelegate ()
+
+@end
+
+@implementation AppDelegate
+
+
+- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
+    // Override point for customization after application launch.
+    return YES;
+}
+
+- (void)applicationWillResignActive:(UIApplication *)application {
+    // Sent when the application is about to move from active to inactive state. This can occur for certain types of temporary interruptions (such as an incoming phone call or SMS message) or when the user quits the application and it begins the transition to the background state.
+    // Use this method to pause ongoing tasks, disable timers, and throttle down OpenGL ES frame rates. Games should use this method to pause the game.
+}
+
+- (void)applicationDidEnterBackground:(UIApplication *)application {
+    // Use this method to release shared resources, save user data, invalidate timers, and store enough application state information to restore your application to its current state in case it is terminated later.
+    // If your application supports background execution, this method is called instead of applicationWillTerminate: when the user quits.
+}
+
+- (void)applicationWillEnterForeground:(UIApplication *)application {
+    // Called as part of the transition from the background to the inactive state; here you can undo many of the changes made on entering the background.
+}
+
+- (void)applicationDidBecomeActive:(UIApplication *)application {
+    // Restart any tasks that were paused (or not yet started) while the application was inactive. If the application was previously in the background, optionally refresh the user interface.
+}
+
+- (void)applicationWillTerminate:(UIApplication *)application {
+    // Called when the application is about to terminate. Save data if appropriate. See also applicationDidEnterBackground:.
+}
+
+@end
diff --git a/154-xcconfig-files/ConfigDemo/ConfigDemo/Application.xcconfig b/154-xcconfig-files/ConfigDemo/ConfigDemo/Application.xcconfig
new file mode 100644
index 0000000..87ac452
--- /dev/null
+++ b/154-xcconfig-files/ConfigDemo/ConfigDemo/Application.xcconfig
@@ -0,0 +1,37 @@
+//
+//  Application.xcconfig
+//  ConfigDemo
+//
+//  Created by Ben Scheirman on 1/24/15.
+//  Copyright (c) 2015 NSScreencast. All rights reserved.
+//
+
+SDKROOT = iphoneos
+CODE_SIGN_IDENTITY[sdk=iphoneos*] = iPhone Developer
+IPHONEOS_DEPLOYMENT_TARGET = 8.1
+
+ALWAYS_SEARCH_USER_PATHS = NO
+GCC_DYNAMIC_NO_PIC = NO
+GCC_OPTIMIZATION_LEVEL = 0
+GCC_SYMBOLS_PRIVATE_EXTERN = NO
+GCC_C_LANGUAGE_STANDARD = gnu99
+CLANG_CXX_LANGUAGE_STANDARD = gnu++0x
+CLANG_CXX_LIBRARY = libc++
+CLANG_ENABLE_MODULES = YES
+CLANG_ENABLE_OBJC_ARC = YES
+ENABLE_STRICT_OBJC_MSGSEND = YES
+CLANG_WARN_EMPTY_BODY = YES
+CLANG_WARN_BOOL_CONVERSION = YES
+CLANG_WARN_CONSTANT_CONVERSION = YES
+GCC_WARN_64_TO_32_BIT_CONVERSION = YES
+CLANG_WARN_ENUM_CONVERSION = YES
+CLANG_WARN_INT_CONVERSION = YES
+GCC_WARN_ABOUT_RETURN_TYPE = YES_ERROR
+GCC_WARN_UNINITIALIZED_AUTOS = YES_AGGRESSIVE
+CLANG_WARN_UNREACHABLE_CODE = YES
+GCC_WARN_UNUSED_FUNCTION = YES
+GCC_WARN_UNUSED_VARIABLE = YES
+CLANG_WARN_DIRECT_OBJC_ISA_USAGE = YES_ERROR
+CLANG_WARN__DUPLICATE_METHOD_MATCH = YES
+GCC_WARN_UNDECLARED_SELECTOR = YES
+CLANG_WARN_OBJC_ROOT_CLASS = YES_ERROR
\ No newline at end of file
diff --git a/154-xcconfig-files/ConfigDemo/ConfigDemo/Base.lproj/LaunchScreen.xib b/154-xcconfig-files/ConfigDemo/ConfigDemo/Base.lproj/LaunchScreen.xib
new file mode 100644
index 0000000..ff48da4
--- /dev/null
+++ b/154-xcconfig-files/ConfigDemo/ConfigDemo/Base.lproj/LaunchScreen.xib
@@ -0,0 +1,41 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<document type="com.apple.InterfaceBuilder3.CocoaTouch.XIB" version="3.0" toolsVersion="6214" systemVersion="14A314h" targetRuntime="iOS.CocoaTouch" propertyAccessControl="none" useAutolayout="YES" launchScreen="YES" useTraitCollections="YES">
+    <dependencies>
+        <plugIn identifier="com.apple.InterfaceBuilder.IBCocoaTouchPlugin" version="6207"/>
+        <capability name="Constraints with non-1.0 multipliers" minToolsVersion="5.1"/>
+    </dependencies>
+    <objects>
+        <placeholder placeholderIdentifier="IBFilesOwner" id="-1" userLabel="File's Owner"/>
+        <placeholder placeholderIdentifier="IBFirstResponder" id="-2" customClass="UIResponder"/>
+        <view contentMode="scaleToFill" id="iN0-l3-epB">
+            <rect key="frame" x="0.0" y="0.0" width="480" height="480"/>
+            <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES"/>
+            <subviews>
+                <label opaque="NO" clipsSubviews="YES" userInteractionEnabled="NO" contentMode="left" horizontalHuggingPriority="251" verticalHuggingPriority="251" text="  Copyright (c) 2015 NSScreencast. All rights reserved." textAlignment="center" lineBreakMode="tailTruncation" baselineAdjustment="alignBaselines" minimumFontSize="9" translatesAutoresizingMaskIntoConstraints="NO" id="8ie-xW-0ye">
+                    <rect key="frame" x="20" y="439" width="441" height="21"/>
+                    <fontDescription key="fontDescription" type="system" pointSize="17"/>
+                    <color key="textColor" cocoaTouchSystemColor="darkTextColor"/>
+                    <nil key="highlightedColor"/>
+                </label>
+                <label opaque="NO" clipsSubviews="YES" userInteractionEnabled="NO" contentMode="left" horizontalHuggingPriority="251" verticalHuggingPriority="251" text="ConfigDemo" textAlignment="center" lineBreakMode="middleTruncation" baselineAdjustment="alignBaselines" minimumFontSize="18" translatesAutoresizingMaskIntoConstraints="NO" id="kId-c2-rCX">
+                    <rect key="frame" x="20" y="140" width="441" height="43"/>
+                    <fontDescription key="fontDescription" type="boldSystem" pointSize="36"/>
+                    <color key="textColor" cocoaTouchSystemColor="darkTextColor"/>
+                    <nil key="highlightedColor"/>
+                </label>
+            </subviews>
+            <color key="backgroundColor" white="1" alpha="1" colorSpace="custom" customColorSpace="calibratedWhite"/>
+            <constraints>
+                <constraint firstItem="kId-c2-rCX" firstAttribute="centerY" secondItem="iN0-l3-epB" secondAttribute="bottom" multiplier="1/3" constant="1" id="5cJ-9S-tgC"/>
+                <constraint firstAttribute="centerX" secondItem="kId-c2-rCX" secondAttribute="centerX" id="Koa-jz-hwk"/>
+                <constraint firstAttribute="bottom" secondItem="8ie-xW-0ye" secondAttribute="bottom" constant="20" id="Kzo-t9-V3l"/>
+                <constraint firstItem="8ie-xW-0ye" firstAttribute="leading" secondItem="iN0-l3-epB" secondAttribute="leading" constant="20" symbolic="YES" id="MfP-vx-nX0"/>
+                <constraint firstAttribute="centerX" secondItem="8ie-xW-0ye" secondAttribute="centerX" id="ZEH-qu-HZ9"/>
+                <constraint firstItem="kId-c2-rCX" firstAttribute="leading" secondItem="iN0-l3-epB" secondAttribute="leading" constant="20" symbolic="YES" id="fvb-Df-36g"/>
+            </constraints>
+            <nil key="simulatedStatusBarMetrics"/>
+            <freeformSimulatedSizeMetrics key="simulatedDestinationMetrics"/>
+            <point key="canvasLocation" x="548" y="455"/>
+        </view>
+    </objects>
+</document>
diff --git a/154-xcconfig-files/ConfigDemo/ConfigDemo/Base.lproj/Main.storyboard b/154-xcconfig-files/ConfigDemo/ConfigDemo/Base.lproj/Main.storyboard
new file mode 100644
index 0000000..d912f9d
--- /dev/null
+++ b/154-xcconfig-files/ConfigDemo/ConfigDemo/Base.lproj/Main.storyboard
@@ -0,0 +1,25 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<document type="com.apple.InterfaceBuilder3.CocoaTouch.Storyboard.XIB" version="3.0" toolsVersion="6211" systemVersion="14A298i" targetRuntime="iOS.CocoaTouch" propertyAccessControl="none" useAutolayout="YES" useTraitCollections="YES" initialViewController="vXZ-lx-hvc">
+    <dependencies>
+        <plugIn identifier="com.apple.InterfaceBuilder.IBCocoaTouchPlugin" version="6204"/>
+    </dependencies>
+    <scenes>
+        <!--View Controller-->
+        <scene sceneID="ufC-wZ-h7g">
+            <objects>
+                <viewController id="vXZ-lx-hvc" customClass="ViewController" customModuleProvider="" sceneMemberID="viewController">
+                    <layoutGuides>
+                        <viewControllerLayoutGuide type="top" id="jyV-Pf-zRb"/>
+                        <viewControllerLayoutGuide type="bottom" id="2fi-mo-0CV"/>
+                    </layoutGuides>
+                    <view key="view" contentMode="scaleToFill" id="kh9-bI-dsS">
+                        <rect key="frame" x="0.0" y="0.0" width="600" height="600"/>
+                        <autoresizingMask key="autoresizingMask" flexibleMaxX="YES" flexibleMaxY="YES"/>
+                        <color key="backgroundColor" white="1" alpha="1" colorSpace="custom" customColorSpace="calibratedWhite"/>
+                    </view>
+                </viewController>
+                <placeholder placeholderIdentifier="IBFirstResponder" id="x5A-6p-PRh" sceneMemberID="firstResponder"/>
+            </objects>
+        </scene>
+    </scenes>
+</document>
diff --git a/154-xcconfig-files/ConfigDemo/ConfigDemo/Debug.xcconfig b/154-xcconfig-files/ConfigDemo/ConfigDemo/Debug.xcconfig
new file mode 100644
index 0000000..9b56dff
--- /dev/null
+++ b/154-xcconfig-files/ConfigDemo/ConfigDemo/Debug.xcconfig
@@ -0,0 +1,14 @@
+//
+//  Debug.xcconfig
+//  ConfigDemo
+//
+//  Created by Ben Scheirman on 1/24/15.
+//  Copyright (c) 2015 NSScreencast. All rights reserved.
+//
+
+#include "Shared.xcconfig"
+
+ONLY_ACTIVE_ARCH = YES
+COPY_PHASE_STRIP = NO
+MTL_ENABLE_DEBUG_INFO = YES
+GCC_PREPROCESSOR_DEFINITIONS = DEBUG=1 $(inherited)
diff --git a/154-xcconfig-files/ConfigDemo/ConfigDemo/Images.xcassets/AppIcon.appiconset/Contents.json b/154-xcconfig-files/ConfigDemo/ConfigDemo/Images.xcassets/AppIcon.appiconset/Contents.json
new file mode 100644
index 0000000..118c98f
--- /dev/null
+++ b/154-xcconfig-files/ConfigDemo/ConfigDemo/Images.xcassets/AppIcon.appiconset/Contents.json
@@ -0,0 +1,38 @@
+{
+  "images" : [
+    {
+      "idiom" : "iphone",
+      "size" : "29x29",
+      "scale" : "2x"
+    },
+    {
+      "idiom" : "iphone",
+      "size" : "29x29",
+      "scale" : "3x"
+    },
+    {
+      "idiom" : "iphone",
+      "size" : "40x40",
+      "scale" : "2x"
+    },
+    {
+      "idiom" : "iphone",
+      "size" : "40x40",
+      "scale" : "3x"
+    },
+    {
+      "idiom" : "iphone",
+      "size" : "60x60",
+      "scale" : "2x"
+    },
+    {
+      "idiom" : "iphone",
+      "size" : "60x60",
+      "scale" : "3x"
+    }
+  ],
+  "info" : {
+    "version" : 1,
+    "author" : "xcode"
+  }
+}
\ No newline at end of file
diff --git a/154-xcconfig-files/ConfigDemo/ConfigDemo/Info.plist b/154-xcconfig-files/ConfigDemo/ConfigDemo/Info.plist
new file mode 100644
index 0000000..0065710
--- /dev/null
+++ b/154-xcconfig-files/ConfigDemo/ConfigDemo/Info.plist
@@ -0,0 +1,49 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>CFBundleDevelopmentRegion</key>
+	<string>en</string>
+	<key>CFBundleExecutable</key>
+	<string>$(EXECUTABLE_NAME)</string>
+	<key>CFBundleIdentifier</key>
+	<string>com.nsscreencast.$(PRODUCT_NAME:rfc1034identifier)</string>
+	<key>CFBundleInfoDictionaryVersion</key>
+	<string>6.0</string>
+	<key>CFBundleName</key>
+	<string>$(PRODUCT_NAME)</string>
+	<key>CFBundlePackageType</key>
+	<string>APPL</string>
+	<key>CFBundleShortVersionString</key>
+	<string>1.0</string>
+	<key>CFBundleSignature</key>
+	<string>????</string>
+	<key>CFBundleVersion</key>
+	<string>1</string>
+	<key>LSRequiresIPhoneOS</key>
+	<true/>
+	<key>UILaunchStoryboardName</key>
+	<string>LaunchScreen</string>
+	<key>UIMainStoryboardFile</key>
+	<string>Main</string>
+	<key>UIRequiredDeviceCapabilities</key>
+	<array>
+		<string>armv7</string>
+	</array>
+	<key>AppSettings</key>
+	<dict>
+		<key>GoogleAnalyticsKey</key>
+		<string>${GOOGLE_ANALYTICS_KEY}</string>
+		<key>FacebookAppID</key>
+		<string>${FACEBOOK_APP_ID}</string>
+		<key>ApiUrl</key>
+		<string>${API_URL}</string>
+	</dict>
+	<key>UISupportedInterfaceOrientations</key>
+	<array>
+		<string>UIInterfaceOrientationPortrait</string>
+		<string>UIInterfaceOrientationLandscapeLeft</string>
+		<string>UIInterfaceOrientationLandscapeRight</string>
+	</array>
+</dict>
+</plist>
diff --git a/154-xcconfig-files/ConfigDemo/ConfigDemo/Release.xcconfig b/154-xcconfig-files/ConfigDemo/ConfigDemo/Release.xcconfig
new file mode 100644
index 0000000..1f390fa
--- /dev/null
+++ b/154-xcconfig-files/ConfigDemo/ConfigDemo/Release.xcconfig
@@ -0,0 +1,14 @@
+//
+//  Release.xcconfig
+//  ConfigDemo
+//
+//  Created by Ben Scheirman on 1/24/15.
+//  Copyright (c) 2015 NSScreencast. All rights reserved.
+//
+
+#include "Shared.xcconfig"
+
+VALIDATE_PRODUCT = YES
+COPY_PHASE_STRIP = YES
+MTL_ENABLE_DEBUG_INFO = NO
+ENABLE_NS_ASSERTIONS = NO
diff --git a/154-xcconfig-files/ConfigDemo/ConfigDemo/Shared.xcconfig b/154-xcconfig-files/ConfigDemo/ConfigDemo/Shared.xcconfig
new file mode 100644
index 0000000..6d077e5
--- /dev/null
+++ b/154-xcconfig-files/ConfigDemo/ConfigDemo/Shared.xcconfig
@@ -0,0 +1,12 @@
+//
+//  Shared.xcconfig
+//  ConfigDemo
+//
+//  Created by Ben Scheirman on 1/24/15.
+//  Copyright (c) 2015 NSScreencast. All rights reserved.
+//
+
+ASSETCATALOG_COMPILER_APPICON_NAME = AppIcon
+LD_RUNPATH_SEARCH_PATHS = $(inherited) @executable_path/Frameworks
+INFOPLIST_FILE = ConfigDemo/Info.plist
+PRODUCT_NAME = $(TARGET_NAME)
\ No newline at end of file
diff --git a/154-xcconfig-files/ConfigDemo/ConfigDemo/ViewController.h b/154-xcconfig-files/ConfigDemo/ConfigDemo/ViewController.h
new file mode 100644
index 0000000..67ea768
--- /dev/null
+++ b/154-xcconfig-files/ConfigDemo/ConfigDemo/ViewController.h
@@ -0,0 +1,15 @@
+//
+//  ViewController.h
+//  ConfigDemo
+//
+//  Created by Ben Scheirman on 1/24/15.
+//  Copyright (c) 2015 NSScreencast. All rights reserved.
+//
+
+#import <UIKit/UIKit.h>
+
+@interface ViewController : UIViewController
+
+
+@end
+
diff --git a/154-xcconfig-files/ConfigDemo/ConfigDemo/ViewController.m b/154-xcconfig-files/ConfigDemo/ConfigDemo/ViewController.m
new file mode 100644
index 0000000..fbc0e1f
--- /dev/null
+++ b/154-xcconfig-files/ConfigDemo/ConfigDemo/ViewController.m
@@ -0,0 +1,27 @@
+//
+//  ViewController.m
+//  ConfigDemo
+//
+//  Created by Ben Scheirman on 1/24/15.
+//  Copyright (c) 2015 NSScreencast. All rights reserved.
+//
+
+#import "ViewController.h"
+
+@interface ViewController ()
+
+@end
+
+@implementation ViewController
+
+- (void)viewDidLoad {
+    [super viewDidLoad];
+    // Do any additional setup after loading the view, typically from a nib.
+}
+
+- (void)didReceiveMemoryWarning {
+    [super didReceiveMemoryWarning];
+    // Dispose of any resources that can be recreated.
+}
+
+@end
diff --git a/154-xcconfig-files/ConfigDemo/ConfigDemo/main.m b/154-xcconfig-files/ConfigDemo/ConfigDemo/main.m
new file mode 100644
index 0000000..547f0ce
--- /dev/null
+++ b/154-xcconfig-files/ConfigDemo/ConfigDemo/main.m
@@ -0,0 +1,16 @@
+//
+//  main.m
+//  ConfigDemo
+//
+//  Created by Ben Scheirman on 1/24/15.
+//  Copyright (c) 2015 NSScreencast. All rights reserved.
+//
+
+#import <UIKit/UIKit.h>
+#import "AppDelegate.h"
+
+int main(int argc, char * argv[]) {
+    @autoreleasepool {
+        return UIApplicationMain(argc, argv, nil, NSStringFromClass([AppDelegate class]));
+    }
+}