diff --git a/packages/flutter_tools/lib/src/ios/mac.dart b/packages/flutter_tools/lib/src/ios/mac.dart
index 413b33a..00e4e2e 100644
--- a/packages/flutter_tools/lib/src/ios/mac.dart
+++ b/packages/flutter_tools/lib/src/ios/mac.dart
@@ -3,9 +3,10 @@
 // found in the LICENSE file.
 
 import 'dart:async';
-import 'dart:convert' show JSON;
+import 'dart:convert' show JSON, UTF8;
 
 import 'package:meta/meta.dart';
+import 'package:quiver/strings.dart';
 
 import '../application_package.dart';
 import '../base/common.dart';
@@ -145,6 +146,10 @@
     return new XcodeBuildResult(success: false);
   }
 
+  String developmentTeam;
+  if (codesign && mode != BuildMode.release && buildForDevice)
+    developmentTeam = await getCodeSigningIdentityDevelopmentTeam(app);
+
   // Before the build, all service definitions must be updated and the dylibs
   // copied over to a location that is suitable for Xcodebuild to find them.
   final Directory appDirectory = fs.directory(app.appDirectory);
@@ -171,6 +176,9 @@
     'ONLY_ACTIVE_ARCH=YES',
   ];
 
+  if (developmentTeam != null)
+    commands.add('DEVELOPMENT_TEAM=$developmentTeam');
+
   final List<FileSystemEntity> contents = fs.directory(app.appDirectory).listSync();
   for (FileSystemEntity entity in contents) {
     if (fs.path.extension(entity.path) == '.xcworkspace') {
@@ -281,7 +289,7 @@
           !checkBuildSettings.stdout?.contains(new RegExp(r'\bPROVISIONING_PROFILE\b')) == true) {
         printError('''
 ═══════════════════════════════════════════════════════════════════════════════════
-Building an iOS app requires a selected Development Team with a Provisioning Profile
+Building a deployable iOS app requires a selected Development Team with a Provisioning Profile
 Please ensure that a Development Team is selected by:
   1- Opening the Flutter project's Xcode target with
        open ios/Runner.xcworkspace
@@ -354,6 +362,118 @@
   return true;
 }
 
+final RegExp _securityFindIdentityDeveloperIdentityExtractionPattern =
+    new RegExp(r'^\s*\d+\).+"(.+Developer.+)"$');
+final RegExp _securityFindIdentityCertificateCnExtractionPattern = new RegExp(r'.*\(([a-zA-Z0-9]+)\)');
+final RegExp _certificateOrganizationalUnitExtractionPattern = new RegExp(r'OU=([a-zA-Z0-9]+)');
+
+/// Given a [BuildableIOSApp], this will try to find valid development code
+/// signing identities in the user's keychain prompting a choice if multiple
+/// are found.
+///
+/// Will return null if none are found, if the user cancels or if the Xcode
+/// project has a development team set in the project's build settings.
+Future<String> getCodeSigningIdentityDevelopmentTeam(BuildableIOSApp iosApp) async{
+  if (iosApp.buildSettings == null)
+    return null;
+
+  // If the user already has it set in the project build settings itself,
+  // continue with that.
+  if (isNotEmpty(iosApp.buildSettings['DEVELOPMENT_TEAM'])) {
+    printStatus(
+      'Automatically signing iOS for device deployment using specified development '
+      'team in Xcode project: ${iosApp.buildSettings['DEVELOPMENT_TEAM']}'
+    );
+    return null;
+  }
+
+  if (isNotEmpty(iosApp.buildSettings['PROVISIONING_PROFILE']))
+    return null;
+
+  // If the user's environment is missing the tools needed to find and read
+  // certificates, abandon. Tools should be pre-equipped on macOS.
+  if (!exitsHappy(<String>['which', 'security'])
+      || !exitsHappy(<String>['which', 'openssl']))
+    return null;
+
+  final List<String> findIdentityCommand =
+      <String>['security', 'find-identity', '-p', 'codesigning', '-v'];
+  final List<String> validCodeSigningIdentities = runCheckedSync(findIdentityCommand)
+      .split('\n')
+      .map<String>((String outputLine) {
+        return _securityFindIdentityDeveloperIdentityExtractionPattern.firstMatch(outputLine)?.group(1);
+      })
+      .where((String identityCN) => isNotEmpty(identityCN))
+      .toSet() // Unique.
+      .toList();
+
+  final String signingIdentity = _chooseSigningIdentity(validCodeSigningIdentities);
+
+  // If none are chosen.
+  if (signingIdentity == null)
+    return null;
+
+  printStatus('Signing iOS app for device deployment using developer identity: "$signingIdentity"');
+
+  final String signingCertificateId =
+      _securityFindIdentityCertificateCnExtractionPattern.firstMatch(signingIdentity)?.group(1);
+
+  // If `security`'s output format changes, we'd have to update this
+  if (signingCertificateId == null)
+    return null;
+
+  final String signingCertificate = runCheckedSync(
+    <String>['security', 'find-certificate', '-c', signingCertificateId, '-p']
+  );
+
+  final Process opensslProcess = await runCommand(
+    <String>['openssl', 'x509', '-subject']
+  );
+  opensslProcess.stdin
+      ..write(signingCertificate)
+      ..close();
+
+  final String opensslOutput = await UTF8.decodeStream(opensslProcess.stdout);
+  opensslProcess.stderr.drain<String>();
+
+  if (await opensslProcess.exitCode != 0) {
+    return null;
+  }
+
+  return _certificateOrganizationalUnitExtractionPattern.firstMatch(opensslOutput)?.group(1);
+}
+
+String _chooseSigningIdentity(List<String> validCodeSigningIdentities) {
+  // The user has no valid code signing identities.
+  if (validCodeSigningIdentities.isEmpty) {
+    printError(
+      '''
+═══════════════════════════════════════════════════════════════════════════════════
+No valid code signing certificates were found
+Please ensure that you have a valid Development Team with valid iOS Development Certificates
+associated with your Apple ID by:
+  1- Opening the Xcode application
+  2- Go to Xcode->Preferences->Accounts
+  3- Make sure that you're signed in with your Apple ID via the '+' button on the bottom left
+  4- Make sure that you have development certificates available by signing up to Apple
+     Developer Program and/or downloading available profiles as needed.
+For more information, please visit:
+  https://developer.apple.com/library/content/documentation/IDEs/Conceptual/AppDistributionGuide/MaintainingCertificates/MaintainingCertificates.html
+
+Or run on an iOS simulator without code signing
+═══════════════════════════════════════════════════════════════════════════════════''',
+      emphasis: true
+    );
+    throwToolExit('No development certificates available to code sign app for device deployment');
+  }
+
+  // TODO(xster): let the user choose one.
+  if (validCodeSigningIdentities.isNotEmpty)
+    return validCodeSigningIdentities.first;
+
+  return null;
+}
+
 final String noCocoaPodsConsequence = '''
   CocoaPods is used to retrieve the iOS platform side's plugin code that responds to your plugin usage on the Dart side.
   Without resolving iOS dependencies with CocoaPods, plugins will not work on iOS.
diff --git a/packages/flutter_tools/lib/src/ios/xcodeproj.dart b/packages/flutter_tools/lib/src/ios/xcodeproj.dart
index aa77254..6b66067 100644
--- a/packages/flutter_tools/lib/src/ios/xcodeproj.dart
+++ b/packages/flutter_tools/lib/src/ios/xcodeproj.dart
@@ -77,11 +77,10 @@
 
 /// Substitutes variables in [str] with their values from the specified Xcode
 /// project and target.
-String substituteXcodeVariables(String str, String xcodeProjPath, String target) {
+String substituteXcodeVariables(String str, Map<String, String> xcodeBuildSettings) {
   final Iterable<Match> matches = _varExpr.allMatches(str);
   if (matches.isEmpty)
     return str;
 
-  final Map<String, String> settings = getXcodeBuildSettings(xcodeProjPath, target);
-  return str.replaceAllMapped(_varExpr, (Match m) => settings[m[1]] ?? m[0]);
+  return str.replaceAllMapped(_varExpr, (Match m) => xcodeBuildSettings[m[1]] ?? m[0]);
 }