diff --git a/firmware/apps/example_1.c b/firmware/apps/example_1.c
new file mode 100644
index 0000000..6b02ee7
--- /dev/null
+++ b/firmware/apps/example_1.c
@@ -0,0 +1,19 @@
+#include <avr/io.h>
+#include <pentabug/app.h>
+
+// was bedeuten die einzelnen Worte?
+// was passiert?
+// geht das einfacher?
+
+static void example(void) {
+	if(!(PINB & 1)) {
+		PORTD &= ~(1 << 4);
+	}
+
+
+	if(!(PINB & 2)) {
+		PORTC &= ~(1 << 2);
+	}
+}
+
+REG(example);
diff --git a/firmware/apps/example_2.c b/firmware/apps/example_2.c
new file mode 100644
index 0000000..3a5fabe
--- /dev/null
+++ b/firmware/apps/example_2.c
@@ -0,0 +1,18 @@
+#include <pentabug/hal.h>
+#include <pentabug/app.h>
+
+// was erwartest du das passiert?
+// wie kann man das Problem lösen?
+
+static void example(void) {
+	if(button_state(LEFT)) {
+		led_inv(LEFT);
+	}
+
+
+	if(button_state(RIGHT)) {
+		motor_inv();
+	}
+}
+
+REG(example);
diff --git a/firmware/apps/example_3.c b/firmware/apps/example_3.c
new file mode 100644
index 0000000..239a2f2
--- /dev/null
+++ b/firmware/apps/example_3.c
@@ -0,0 +1,24 @@
+#include <pentabug/hal.h>
+#include <pentabug/app.h>
+#include <pentabug/music.h>
+
+static void example(void) {
+	if(button_clicked(LEFT)) {
+		set_note(NOTE_C, 4);
+		wait_ms(500);
+		set_note(NOTE_D, 4);
+		wait_ms(500);
+		stop_note();
+	}
+
+
+	if(button_clicked(RIGHT)) {
+		set_note(NOTE_D, 4);
+		wait_ms(500);
+		set_note(NOTE_C, 4);
+		wait_ms(500);
+		stop_note();
+	}
+}
+
+REG(example);
diff --git a/firmware/apps/example_4.c b/firmware/apps/example_4.c
new file mode 100644
index 0000000..d43d2fc
--- /dev/null
+++ b/firmware/apps/example_4.c
@@ -0,0 +1,39 @@
+#include <pentabug/hal.h>
+#include <pentabug/app.h>
+
+// was passiert?
+// gibt es probleme?
+// wie kann man das problem lösen?
+
+static void init(void) {
+	led_on(RIGHT);
+	led_on(LEFT);
+}
+
+static void example(void) {
+	led_inv(LEFT);
+	led_inv(RIGHT);
+
+	wait_ms(500);
+	
+	led_inv(LEFT);
+
+	wait_ms(500);
+
+	led_inv(RIGHT);
+
+	wait_ms(500);
+
+	if(button_clicked(LEFT)) {
+		motor_inv();
+		wait_ms(500);
+		motor_inv();
+		wait_ms(500);
+		motor_inv();
+		wait_ms(500);
+		motor_inv();
+		wait_ms(500);
+	}
+}
+
+REGISTER(example, init, NULL);