diff --git a/app/CMakeLists.txt b/app/CMakeLists.txt
index efa349052cf..af0b023c489 100644
--- a/app/CMakeLists.txt
+++ b/app/CMakeLists.txt
@@ -56,6 +56,7 @@ if ((NOT CONFIG_ZMK_SPLIT) OR CONFIG_ZMK_SPLIT_ROLE_CENTRAL)
   target_sources_ifdef(CONFIG_ZMK_BEHAVIOR_SENSOR_ROTATE_COMMON app PRIVATE src/behaviors/behavior_sensor_rotate_common.c)
   target_sources(app PRIVATE src/combo.c)
   target_sources(app PRIVATE src/behaviors/behavior_tap_dance.c)
+  target_sources(app PRIVATE src/behaviors/behavior_bottom.c)
   target_sources(app PRIVATE src/behavior_queue.c)
   target_sources(app PRIVATE src/conditional_layer.c)
   target_sources(app PRIVATE src/endpoints.c)
diff --git a/app/dts/behaviors.dtsi b/app/dts/behaviors.dtsi
index b3502cbbc13..386bc391231 100644
--- a/app/dts/behaviors.dtsi
+++ b/app/dts/behaviors.dtsi
@@ -18,4 +18,5 @@
 #include <behaviors/caps_word.dtsi>
 #include <behaviors/key_repeat.dtsi>
 #include <behaviors/backlight.dtsi>
-#include <behaviors/macros.dtsi>
\ No newline at end of file
+#include <behaviors/macros.dtsi>
+#include <behaviors/bottom.dtsi>
diff --git a/app/dts/behaviors/bottom.dtsi b/app/dts/behaviors/bottom.dtsi
new file mode 100644
index 00000000000..0336eb3701d
--- /dev/null
+++ b/app/dts/behaviors/bottom.dtsi
@@ -0,0 +1,16 @@
+/*
+ * Copyright (c) 2021 The ZMK Contributors
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+ / {
+    behaviors {
+        /omit-if-no-ref/ bottom: behavior_bottom {
+            compatible = "zmk,behavior-bottom";
+            label = "BOTTOM";
+            #binding-cells = <0>;
+      delay_ms = <10>;
+        };
+    };
+};
diff --git a/app/dts/bindings/behaviors/zmk,behavior-bottom.yaml b/app/dts/bindings/behaviors/zmk,behavior-bottom.yaml
new file mode 100644
index 00000000000..9f3913e7af1
--- /dev/null
+++ b/app/dts/bindings/behaviors/zmk,behavior-bottom.yaml
@@ -0,0 +1,13 @@
+# Copyright (c) 2020 The ZMK Contributors
+# SPDX-License-Identifier: MIT
+
+description: Keyboard Keysmash Behavior
+
+compatible: "zmk,behavior-bottom"
+
+include: zero_param.yaml
+
+properties:
+  delay_ms:
+    type: int
+    required: true
diff --git a/app/src/behaviors/behavior_bottom.c b/app/src/behaviors/behavior_bottom.c
new file mode 100644
index 00000000000..6e4501cc106
--- /dev/null
+++ b/app/src/behaviors/behavior_bottom.c
@@ -0,0 +1,70 @@
+/*
+ * Copyright (c) 2021 The ZMK Contributors
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+#define DT_DRV_COMPAT zmk_behavior_bottom
+
+#include <device.h>
+#include <drivers/behavior.h>
+#include <kernel.h>
+#include <logging/log.h>
+#include <zmk/behavior.h>
+#include <random/rand32.h>
+#include <zmk/event_manager.h>
+#include <zmk/events/keycode_state_changed.h>
+
+LOG_MODULE_DECLARE(zmk, CONFIG_ZMK_LOG_LEVEL);
+
+#if DT_HAS_COMPAT_STATUS_OKAY(DT_DRV_COMPAT)
+
+struct behavior_bottom_config {
+    int delay_ms;
+};
+
+static void zmk_bottom_tick(struct k_work *work) {
+    int key = (sys_rand32_get() % 26) + 4;
+    ZMK_EVENT_RAISE(zmk_keycode_state_changed_from_encoded(key, true, k_uptime_get()));
+    k_msleep(5);
+    ZMK_EVENT_RAISE(zmk_keycode_state_changed_from_encoded(key, false, k_uptime_get()));
+}
+
+K_WORK_DEFINE(bottom_work, zmk_bottom_tick);
+
+static void zmk_bottom_tick_handler(struct k_timer *timer) { k_work_submit(&bottom_work); }
+
+K_TIMER_DEFINE(bottom_tick, zmk_bottom_tick_handler, NULL);
+
+static int on_bottom_binding_pressed(struct zmk_behavior_binding *binding,
+                                     struct zmk_behavior_binding_event event) {
+    const struct device *dev = device_get_binding(binding->behavior_dev);
+    const struct behavior_bottom_config *cfg = dev->config;
+
+    k_timer_start(&bottom_tick, K_NO_WAIT, K_MSEC(cfg->delay_ms));
+
+    return ZMK_BEHAVIOR_OPAQUE;
+}
+
+static int on_bottom_binding_released(struct zmk_behavior_binding *binding,
+                                      struct zmk_behavior_binding_event event) {
+    k_timer_stop(&bottom_tick);
+    return ZMK_BEHAVIOR_OPAQUE;
+}
+
+static const struct behavior_driver_api behavior_bottom_driver_api = {
+    .binding_pressed = on_bottom_binding_pressed,
+    .binding_released = on_bottom_binding_released,
+};
+
+static int behavior_bottom_init(const struct device *dev) { return 0; }
+
+static struct behavior_bottom_config behavior_bottom_config = {
+    .delay_ms = DT_INST_PROP(0, delay_ms),
+};
+
+DEVICE_DT_INST_DEFINE(0, behavior_bottom_init, device_pm_control_nop, NULL, &behavior_bottom_config,
+                      APPLICATION, CONFIG_KERNEL_INIT_PRIORITY_DEFAULT,
+                      &behavior_bottom_driver_api);
+
+#endif