diff --git a/smartapps/com-stormwave-doorknock/lights-flash-on-door-knock.src/lights-flash-on-door-knock.groovy b/smartapps/com-stormwave-doorknock/lights-flash-on-door-knock.src/lights-flash-on-door-knock.groovy
new file mode 100644
index 0000000..fff4dc9
--- /dev/null
+++ b/smartapps/com-stormwave-doorknock/lights-flash-on-door-knock.src/lights-flash-on-door-knock.groovy
@@ -0,0 +1,170 @@
+/**
+ *  Lights Flash on Door Knock
+ *
+ *  Copyright 2016 Andrew Cornforth
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
+ *  in compliance with the License. You may obtain a copy of the License at:
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software distributed under the License is distributed
+ *  on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License
+ *  for the specific language governing permissions and limitations under the License.
+ *
+ */
+definition(
+    name: "Lights Flash on Door Knock",
+    namespace: "com.stormwave.doorknock",
+    author: "Andrew Cornforth",
+    description: "Flashes lights when activity is noticed at the door.",
+    category: "Safety & Security",
+    iconUrl: "http://cdn.device-icons.smartthings.com/Lighting/light10-icn.png",
+    iconX2Url: "http://cdn.device-icons.smartthings.com/Lighting/light10-icn@2x.png",
+    iconX3Url: "http://cdn.device-icons.smartthings.com/Lighting/light10-icn@2x.png")
+
+
+preferences {
+	section("Things") 
+    {
+		input "doorsensor", "capability.accelerationSensor", title: "Door Sensor", required: true, multiple: true
+        input "lights", "capability.switch", title:"Lights", required:true, multiple:true
+	}
+    section("Settings")
+    {
+    	input "numFlashes", "number", title:"Number of Flashes", required:true, defaultValue:"5"
+    	input "onFor", "number", title:"Time On (ms)", required:true, defaultValue:"1000"
+    	input "offFor", "number", title:"Time Off (ms)", required:true, defaultValue:"1000"
+	}
+    section("Only If")
+    {
+    	input "switcheson", "capability.switch", title:"Switches Are On", required:false, multiple:true
+    	input "switchesoff", "capability.switch", title:"Switches Are Off", required:false, multiple:true
+    	input "sleepon", "capability.sleepSensor", title:"Thing Is Asleep", required:false, multiple:true
+    	input "sleepoff", "capability.sleepSensor", title:"Thing Is Awake", required:false, multiple:true
+    }
+    section("Or If")
+    {
+    	input "or_switcheson", "capability.switch", title:"Switches Are On", required:false, multiple:true
+    	input "or_switchesoff", "capability.switch", title:"Switches Are Off", required:false, multiple:true
+    	input "or_sleepon", "capability.sleepSensor", title:"Thing Is Asleep", required:false, multiple:true
+    	input "or_sleepoff", "capability.sleepSensor", title:"Thing Is Awake", required:false, multiple:true
+    }
+}
+
+def flashLights()
+{
+    lights.each 
+    { 
+        light ->
+            def delay = 0L
+            if (light.latestValue("switch")=="on")
+            {
+                numFlashes.times 
+                {
+                    light.off(delay: delay)
+                    delay += offFor
+                    light.on(delay: delay)
+                    delay += onFor
+                }
+            }
+	        else
+            {
+                numFlashes.times 
+                {
+                    light.on(delay: delay)
+                    delay += onFor
+                    light.off(delay: delay)
+                    delay += offFor
+                }
+			}
+    }
+}
+
+def installed() {
+	log.debug "Installed with settings: ${settings}"
+
+	initialize()
+}
+
+def updated() {
+	log.debug "Updated with settings: ${settings}"
+
+	unsubscribe()
+	initialize()
+}
+
+def unsubcribe()
+{
+	unsubscribe(doorsensor)
+}
+
+def initialize() 
+{
+	subscribe(doorsensor, "acceleration", activityHandler)
+}
+
+def activityHandler(evt) 
+{
+	if (evt.value=="active")
+    {
+    	// Check conditions
+        def valid = true
+        switcheson.each 
+        { 
+            device ->
+            	if (device.latestValue("switch")=="off") { valid = false; }
+        }
+        if (valid)
+            switchesoff.each 
+            { 
+                device ->
+                    if (device.latestValue("switch")=="on") { valid = false; }
+            }
+        if (valid)
+            sleepon.each 
+            { 
+                device ->
+                    if (device.latestValue("sleeping")=="not sleeping") { valid = false; }
+            }
+        if (valid)
+            sleepoff.each 
+            { 
+                device ->
+                    if (device.latestValue("sleeping")=="sleeping") { valid = false; }
+            }
+            
+        // Check for "or" values if failed first step
+		if (!valid)
+        {
+        	valid = true
+            or_switcheson.each 
+            { 
+                device ->
+                    if (device.latestValue("switch")=="off") { valid = false; }
+            }
+            if (valid)
+                or_switchesoff.each 
+                { 
+                    device ->
+                        if (device.latestValue("switch")=="on") { valid = false; }
+                }
+            if (valid)
+                or_sleepon.each 
+                { 
+                    device ->
+                        if (device.latestValue("sleeping")=="not sleeping") { valid = false; }
+                }
+            if (valid)
+                or_sleepoff.each 
+                { 
+                    device ->
+                        if (device.latestValue("sleeping")=="sleeping") { valid = false; }
+                }
+		}
+        if (valid)
+        {
+    		flashLights()
+        }
+	}
+}
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