diff --git a/InjectionIII.xcodeproj/project.pbxproj b/InjectionIII.xcodeproj/project.pbxproj
index 987a20eb..1a773178 100644
--- a/InjectionIII.xcodeproj/project.pbxproj
+++ b/InjectionIII.xcodeproj/project.pbxproj
@@ -166,6 +166,7 @@
 		BBE490DA1FB2C643003D41BB /* InjectionError.tif */ = {isa = PBXFileReference; lastKnownFileType = image.tiff; path = InjectionError.tif; sourceTree = "<group>"; };
 		BBEB704A1FD28C6F00127711 /* XcodeHash.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = XcodeHash.h; sourceTree = "<group>"; };
 		BBEB704B1FD28C6F00127711 /* XcodeHash.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = XcodeHash.m; sourceTree = "<group>"; };
+		BDB6A7CE21824C800001CF95 /* UserDefaults.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = UserDefaults.h; sourceTree = "<group>"; };
 /* End PBXFileReference section */
 
 /* Begin PBXFrameworksBuildPhase section */
@@ -350,6 +351,7 @@
 				BBCA02581FB112F500E45F0F /* App.icns */,
 				BBCA02091FB0F10400E45F0F /* main.m */,
 				BBCA020B1FB0F10400E45F0F /* InjectionIII.entitlements */,
+				BDB6A7CE21824C800001CF95 /* UserDefaults.h */,
 			);
 			path = InjectionIII;
 			sourceTree = "<group>";
diff --git a/InjectionIII/AppDelegate.mm b/InjectionIII/AppDelegate.mm
index efb19d2e..b4351577 100644
--- a/InjectionIII/AppDelegate.mm
+++ b/InjectionIII/AppDelegate.mm
@@ -18,6 +18,7 @@
 //#import "DDHotKeyCenter.h"
 
 #import "InjectionIII-Swift.h"
+#import "UserDefaults.h"
 
 #ifdef XPROBE_PORT
 #import "../XprobePlugin/Classes/XprobePluginMenuController.h"
@@ -32,7 +33,7 @@ @interface AppDelegate ()
 
 @implementation AppDelegate {
     IBOutlet NSMenu *statusMenu;
-    IBOutlet NSMenuItem *startItem, *xprobeItem, *windowItem;
+    IBOutlet NSMenuItem *startItem, *xprobeItem, *enabledTDDItem, *windowItem;
     IBOutlet NSStatusItem *statusItem;
 }
 
@@ -49,6 +50,10 @@ - (void)applicationDidFinishLaunching:(NSNotification *)aNotification {
     statusItem.enabled = TRUE;
     statusItem.title = @"";
 
+    enabledTDDItem.state = ([[NSUserDefaults standardUserDefaults] boolForKey:UserDefaultsTDDEnabled])
+        ? NSControlStateValueOn
+        : NSControlStateValueOff;
+
     [self setMenuIcon:@"InjectionIdle"];
 #if 0
     [[DDHotKeyCenter sharedHotKeyCenter] registerHotKeyWithKeyCode:kVK_ANSI_Equal
@@ -61,6 +66,15 @@ - (IBAction)openProject:sender {
     [self application:NSApp openFile:nil];
 }
 
+- (IBAction)toggleTDD:(NSMenuItem *)sender {
+    [self toggleState:sender];
+
+    BOOL newSetting = sender.state == NSControlStateValueOn;
+
+    [[NSUserDefaults standardUserDefaults] setBool:newSetting forKey:UserDefaultsTDDEnabled];
+    NSLog(@"sender: %ld", (long)[sender state]);
+}
+
 - (BOOL)application:(NSApplication *)theApplication openFile:(NSString *)filename {
     NSOpenPanel *open = [NSOpenPanel new];
     open.prompt = NSLocalizedString(@"Select Project Directory", @"Project Directory");
diff --git a/InjectionIII/Base.lproj/MainMenu.xib b/InjectionIII/Base.lproj/MainMenu.xib
index 393d9701..80fab245 100644
--- a/InjectionIII/Base.lproj/MainMenu.xib
+++ b/InjectionIII/Base.lproj/MainMenu.xib
@@ -16,6 +16,7 @@
         <customObject id="Voe-Tx-rLC" customClass="AppDelegate">
             <connections>
                 <outlet property="enableWatcher" destination="0iA-WA-gxc" id="vVT-sI-q78"/>
+                <outlet property="enabledTDDItem" destination="cCv-GY-3Rv" id="gWc-O6-aDP"/>
                 <outlet property="startItem" destination="vsd-ll-3nr" id="ODN-wa-BTp"/>
                 <outlet property="statusMenu" destination="V8Q-mq-A2f" id="Epo-HD-J21"/>
                 <outlet property="window" destination="QvC-M9-y7g" id="gIp-Ho-8D9"/>
@@ -619,13 +620,13 @@
                             </menuItem>
                             <menuItem isSeparatorItem="YES" id="hB3-LF-h0Y"/>
                             <menuItem title="Show Sidebar" keyEquivalent="s" id="kIP-vf-haE">
-                                <modifierMask key="keyEquivalentModifierMask" control="YES" command="YES"/>
+                                <modifierMask key="keyEquivalentModifierMask" control="YES" option="YES" command="YES"/>
                                 <connections>
                                     <action selector="toggleSourceList:" target="-1" id="iwa-gc-5KM"/>
                                 </connections>
                             </menuItem>
-                            <menuItem title="Enter Full Screen" keyEquivalent="f" id="4J7-dP-txa">
-                                <modifierMask key="keyEquivalentModifierMask" control="YES" command="YES"/>
+                            <menuItem title="Enter Full Screen" keyEquivalent="↩" id="4J7-dP-txa">
+                                <modifierMask key="keyEquivalentModifierMask" control="YES" option="YES" command="YES"/>
                                 <connections>
                                     <action selector="toggleFullScreen:" target="-1" id="dU3-MA-1Rq"/>
                                 </connections>
@@ -651,7 +652,7 @@
             <windowStyleMask key="styleMask" titled="YES" closable="YES" miniaturizable="YES" resizable="YES"/>
             <windowPositionMask key="initialPositionMask" leftStrut="YES" rightStrut="YES" topStrut="YES" bottomStrut="YES"/>
             <rect key="contentRect" x="335" y="390" width="480" height="360"/>
-            <rect key="screenRect" x="0.0" y="0.0" width="1920" height="1177"/>
+            <rect key="screenRect" x="0.0" y="0.0" width="1680" height="1050"/>
             <view key="contentView" wantsLayer="YES" id="EiT-Mj-1SZ">
                 <rect key="frame" x="0.0" y="0.0" width="480" height="360"/>
                 <autoresizingMask key="autoresizingMask"/>
@@ -690,6 +691,12 @@
                         <action selector="toggleState:" target="Voe-Tx-rLC" id="old-T7-DMa"/>
                     </connections>
                 </menuItem>
+                <menuItem title="Enable TDD" id="cCv-GY-3Rv">
+                    <modifierMask key="keyEquivalentModifierMask"/>
+                    <connections>
+                        <action selector="toggleTDD:" target="Voe-Tx-rLC" id="tqU-Qb-3kf"/>
+                    </connections>
+                </menuItem>
                 <menuItem title="Run Xprobe" id="R6p-Yl-7qz">
                     <modifierMask key="keyEquivalentModifierMask"/>
                     <connections>
diff --git a/InjectionIII/FileWatcher.m b/InjectionIII/FileWatcher.m
index eceeb031..72821371 100644
--- a/InjectionIII/FileWatcher.m
+++ b/InjectionIII/FileWatcher.m
@@ -60,13 +60,16 @@ - (void)filesChanged:(NSArray *)changes;
     NSFileManager *fileManager = [NSFileManager defaultManager];
     NSMutableSet *changed = [NSMutableSet new];
 
-    for (NSString *path in changes)
+    for (NSString *path in changes) {
         if ([path rangeOfString:INJECTABLE_PATTERN
                         options:NSRegularExpressionSearch].location != NSNotFound &&
             [path rangeOfString:@"DerivedData/|InjectionProject/|main.mm?$"
                         options:NSRegularExpressionSearch].location == NSNotFound &&
-            [fileManager fileExistsAtPath:path])
+            [fileManager fileExistsAtPath:path]) {
+
             [changed addObject:path];
+        }
+    }
 
     //NSLog( @"filesChanged: %@", changed );
     if (changed.count)
diff --git a/InjectionIII/Info.plist b/InjectionIII/Info.plist
index dae596e5..4653afd6 100644
--- a/InjectionIII/Info.plist
+++ b/InjectionIII/Info.plist
@@ -19,7 +19,7 @@
 	<key>CFBundleShortVersionString</key>
 	<string>1.2</string>
 	<key>CFBundleVersion</key>
-	<string>1199</string>
+	<string>1287</string>
 	<key>LSApplicationCategoryType</key>
 	<string>public.app-category.developer-tools</string>
 	<key>LSMinimumSystemVersion</key>
diff --git a/InjectionIII/InjectionServer.mm b/InjectionIII/InjectionServer.mm
index f320af16..c120db56 100644
--- a/InjectionIII/InjectionServer.mm
+++ b/InjectionIII/InjectionServer.mm
@@ -14,6 +14,7 @@
 
 #import "Xcode.h"
 #import "XcodeHash.h"
+#import "UserDefaults.h"
 
 #import "InjectionIII-Swift.h"
 
@@ -155,7 +156,16 @@ - (void)runInBackground {
 
     injector = ^(NSArray *changed) {
         NSTimeInterval now = [NSDate timeIntervalSinceReferenceDate];
-        for (NSString *swiftSource in changed)
+        NSMutableArray *changedFiles = [NSMutableArray arrayWithArray:changed];
+
+        if ([[NSUserDefaults standardUserDefaults] boolForKey:UserDefaultsTDDEnabled]) {
+            NSArray *matchedTests = [InjectionServer searchForTestWithFiles:changed
+                                                                projectRoot:projectFile.stringByDeletingLastPathComponent
+                                                                fileManager:[NSFileManager defaultManager]];
+            [changedFiles addObjectsFromArray:matchedTests];
+        }
+
+        for (NSString *swiftSource in changedFiles)
             if (now > lastInjected[swiftSource].doubleValue + MIN_INJECTION_INTERVAL && now > pause) {
                 lastInjected[swiftSource] = [NSNumber numberWithDouble:now];
                 inject(swiftSource);
@@ -197,6 +207,49 @@ - (void)setProject:(NSString *)project {
                    plugin:injector];
 }
 
++ (NSArray *)searchForTestWithFiles:(NSArray *)injectedFiles projectRoot:(NSString *)projectRoot fileManager:(NSFileManager *)fileManager;
+{
+    NSMutableArray *matchedTests = [NSMutableArray array];
+    for (NSString *injectedFile in injectedFiles) {
+        NSString *injectedFileName = [[injectedFile lastPathComponent] stringByDeletingPathExtension];
+        NSURL *projectUrl = [NSURL URLWithString:projectRoot];
+        NSDirectoryEnumerator *enumerator = [fileManager enumeratorAtURL:projectUrl
+                                              includingPropertiesForKeys:@[NSURLNameKey, NSURLIsDirectoryKey]
+                                                                 options:NSDirectoryEnumerationSkipsHiddenFiles
+                                                            errorHandler:^BOOL(NSURL *url, NSError *error)
+                                             {
+                                                 if (error) {
+                                                     NSLog(@"[Error] %@ (%@)", error, url);
+                                                     return NO;
+                                                 }
+
+                                                 return YES;
+                                             }];
+
+
+        for (NSURL *fileURL in enumerator) {
+            NSString *filename;
+            NSNumber *isDirectory;
+
+            [fileURL getResourceValue:&filename forKey:NSURLNameKey error:nil];
+            [fileURL getResourceValue:&isDirectory forKey:NSURLIsDirectoryKey error:nil];
+
+            if ([filename hasPrefix:@"_"] && [isDirectory boolValue]) {
+                [enumerator skipDescendants];
+                continue;
+            }
+
+            if (![isDirectory boolValue] &&
+                ![[filename lastPathComponent] isEqualToString:[injectedFile lastPathComponent]] &&
+                [[filename lowercaseString] containsString:[injectedFileName lowercaseString]]) {
+                [matchedTests addObject:fileURL.path];
+            }
+        }
+    }
+
+    return matchedTests;
+}
+
 - (void)dealloc {
     NSLog(@"- [%@ dealloc]", self);
 }
diff --git a/InjectionIII/UserDefaults.h b/InjectionIII/UserDefaults.h
new file mode 100644
index 00000000..fcbc3da7
--- /dev/null
+++ b/InjectionIII/UserDefaults.h
@@ -0,0 +1,11 @@
+//
+//  UserDefaults.h
+//  InjectionIII
+//
+//  Created by Christoffer Winterkvist on 10/25/18.
+//  Copyright © 2018 John Holdsworth. All rights reserved.
+//
+
+#import "AppDelegate.h"
+
+NSString *const UserDefaultsTDDEnabled = @"Enabled TDD";