Update.

dmenugpu

@@ -0,0 +1,41 @@
+#!/bin/sh
+
+already_in()
+{
+    quick-notify "Gpu Manager" "Already in $new_mode mode"
+}
+
+switch()
+{
+    if sudo envycontrol.py --switch $new_mode; then
+        quick-notify "Gpu Manager" "Switched to $new_mode mode"
+    else
+        quick-notify "Gpu Manager" "Failed to switch to $new_mode mode"
+    fi
+}
+
+case "$(printf "integrated\\nhybrid\\nnvidia" | dmenu -p "Choose gpu mode")" in
+	"integrated") new_mode="integrated";;
+	"nvidia") new_mode="nvidia";;
+  "hybrid") new_mode="hybrid";;
+esac
+
+current_mode=$(envycontrol.py --status | awk '{ print $5 }')
+
+if [ $current_mode = "integrated" ]; then
+    case $new_mode in
+        "integrated") already_in;;
+        "nvidia") quick-notify "Gpu Manager" "You need to first reboot into hybrid mode";;
+        "hybrid") switch;;
+    esac
+elif [ $current_mode = "hybrid" ]; then
+    case $new_mode in
+        "hybrid") already_in;;
+        *) switch;;
+    esac
+elif [ $current_mode = "nvidia" ]; then
+    case $new_mode in
+        "nvidia") already_in;;
+        *) switch;;
+    esac
+fi