diff --git a/doc/plugin/NumPad.md b/doc/plugin/NumPad.md
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+# Kaleidoscope-NumPad
+
+This is a plugin for [Kaleidoscope][fw], that adds a NumPad-specific LED
+effect, along with a way to toggle to a numpad layer, and apply the effect.
+
+## Using the extension
+
+To use the plugin, include the header, and tell the firmware to use it:
+
+```c++
+#include "Kaleidoscope-NumPad.h"
+
+KALEIDOSCOPE_INIT_PLUGINS(NumPad);
+
+void setup() {
+  Kaleidoscope.setup();
+
+  NumPad.color = CRGB(0, 0, 160); // a blue color
+  NumPad.lock_hue = 85; // green
+}
+```
+
+##   Plugin methods
+
+The plugin provides the `NumPad` object, with the following properties:
+
+### `.color`
+
+> This property sets the color that the NumPad keys are highlighted in.
+>
+> The default is `CRGB(160, 0, 0)`, a red color.
+
+### `.lock_hue`
+
+> This property sets the color hue that the NumLock LED breathes in.
+>
+> The default is `170`, a blue hue.
+
+ [fw]: https://github.com/keyboardio/Kaleidoscope
diff --git a/src/Kaleidoscope-NumPad.h b/src/Kaleidoscope-NumPad.h
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+++ b/src/Kaleidoscope-NumPad.h
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+/* Kaleidoscope-NumPad - A NumPad plugin for Kaleidoscope.
+ * Copyright (C) 2017-2018  Keyboard.io, Inc.
+ *
+ * This program is free software: you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License as published by the Free Software
+ * Foundation, version 3.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#include "kaleidoscope/plugin/NumPad.h"
diff --git a/src/kaleidoscope/plugin/NumPad.cpp b/src/kaleidoscope/plugin/NumPad.cpp
new file mode 100644
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+++ b/src/kaleidoscope/plugin/NumPad.cpp
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+/* Kaleidoscope-NumPad - A NumPad plugin for Kaleidoscope.
+ * Copyright (C) 2017-2018  Keyboard.io, Inc.
+ *
+ * This program is free software: you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License as published by the Free Software
+ * Foundation, version 3.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "Kaleidoscope-NumPad.h"
+
+namespace kaleidoscope {
+namespace plugin {
+
+byte NumPad::numpadLayerToggleKeyRow = 255, NumPad::numpadLayerToggleKeyCol = 255;
+uint8_t NumPad::numPadLayer;
+bool NumPad::numlockUnsynced = false;
+bool NumPad::originalNumLockState = false;
+cRGB NumPad::color = CRGB(160, 0, 0);
+uint8_t NumPad::lock_hue = 170;
+
+EventHandlerResult NumPad::onSetup(void) {
+  originalNumLockState = getNumlockState();
+  return EventHandlerResult::OK;
+}
+
+bool NumPad::getNumlockState() {
+  return !!(kaleidoscope::hid::getKeyboardLEDs() & LED_NUM_LOCK);
+}
+
+void NumPad::syncNumlockState(bool state) {
+  bool numLockLEDState = getNumlockState();
+  if (numLockLEDState != state) {
+    kaleidoscope::hid::pressKey(Key_KeypadNumLock);
+  }
+}
+
+
+
+void NumPad::cleanupNumlockState() {
+  if (!numlockUnsynced) {
+    bool numLockLEDState = getNumlockState();
+    ::LEDControl.set_mode(::LEDControl.get_mode_index());
+    if (!originalNumLockState) {
+      syncNumlockState(false);
+      numLockLEDState = false;
+    }
+    originalNumLockState = numLockLEDState;
+    numlockUnsynced = true;
+  }
+
+}
+
+void NumPad::setKeyboardLEDColors(void) {
+  ::LEDControl.set_mode(::LEDControl.get_mode_index());
+
+  for (uint8_t r = 0; r < ROWS; r++) {
+    for (uint8_t c = 0; c < COLS; c++) {
+      Key k = Layer.lookupOnActiveLayer(r, c);
+      Key layer_key = Layer.getKey(numPadLayer, r, c);
+
+      if (k == LockLayer(numPadLayer)) {
+        numpadLayerToggleKeyRow = r;
+        numpadLayerToggleKeyCol = c;
+      }
+
+      if ((k != layer_key) || (k == Key_NoKey) || (k.flags != KEY_FLAGS)) {
+        ::LEDControl.refreshAt(r, c);
+      } else {
+        ::LEDControl.setCrgbAt(r, c, color);
+      }
+    }
+  }
+
+  if ((numpadLayerToggleKeyRow <= ROWS) && (numpadLayerToggleKeyCol <= COLS)) {
+    cRGB lock_color = breath_compute(lock_hue);
+    ::LEDControl.setCrgbAt(numpadLayerToggleKeyRow, numpadLayerToggleKeyCol, lock_color);
+  }
+}
+
+EventHandlerResult NumPad::afterEachCycle() {
+  if (!Layer.isOn(numPadLayer)) {
+    cleanupNumlockState();
+  } else {
+    if (numlockUnsynced)  {
+      // If it's the first time we're in this loop after toggling the Numpad mode on
+      syncNumlockState(true);
+      numlockUnsynced = false;
+    }
+    setKeyboardLEDColors();
+  }
+  return EventHandlerResult::OK;
+}
+
+}
+}
+
+kaleidoscope::plugin::NumPad NumPad;
diff --git a/src/kaleidoscope/plugin/NumPad.h b/src/kaleidoscope/plugin/NumPad.h
new file mode 100644
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--- /dev/null
+++ b/src/kaleidoscope/plugin/NumPad.h
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+/* Kaleidoscope-NumPad - A NumPad plugin for Kaleidoscope.
+ * Copyright (C) 2017-2018  Keyboard.io, Inc.
+ *
+ * This program is free software: you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License as published by the Free Software
+ * Foundation, version 3.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#include "Kaleidoscope-LEDControl.h"
+
+namespace kaleidoscope {
+namespace plugin {
+
+class NumPad : public kaleidoscope::Plugin {
+ public:
+  NumPad(void) {}
+
+  static uint8_t numPadLayer;
+  static cRGB color;
+  static uint8_t lock_hue;
+
+  EventHandlerResult onSetup(void);
+  EventHandlerResult afterEachCycle();
+
+ private:
+
+  void cleanupNumlockState(void);
+  void setKeyboardLEDColors(void);
+  bool getNumlockState(void);
+  void syncNumlockState(bool);
+
+  static uint8_t numpadLayerToggleKeyRow;
+  static uint8_t numpadLayerToggleKeyCol;
+  static bool numlockUnsynced;
+  static bool originalNumLockState;
+};
+}
+}
+
+extern kaleidoscope::plugin::NumPad NumPad;