diff --git a/apps/hardware_test/lcd_data_test_controller.cpp b/apps/hardware_test/lcd_data_test_controller.cpp
index a561cb226..dc9342d63 100644
--- a/apps/hardware_test/lcd_data_test_controller.cpp
+++ b/apps/hardware_test/lcd_data_test_controller.cpp
@@ -34,12 +34,12 @@ void LCDDataTestController::ContentView::layoutSubviews() {
   m_lcdDataStateView.setFrame(KDRect(0, 0, Ion::Display::Width, Ion::Display::Height));
 }
 
-
 void colorPixelBuffer(KDColor * pixels, int numberOfPixels, KDColor c) {
   for (int i = 0; i < numberOfPixels; i++) {
     pixels[i] = c;
   }
 }
+
 bool LCDDataTestController::test() {
   KDColor testColors[] = {
     KDColorRed, KDColorGreen, KDColorBlue,
@@ -62,7 +62,7 @@ bool LCDDataTestController::testDisplayColor(KDColor c) {
 
   KDColor stamp[stampWidth*stampHeight];
 
-  // Test with pushRect
+  // Tiling test with pushRect
   colorPixelBuffer(stamp, stampWidth * stampHeight, c);
   for (int i = 0; i < Ion::Display::Width / stampWidth; i++) {
     for (int j = 0; j < Ion::Display::Height / stampHeight; j++) {
diff --git a/apps/hardware_test/lcd_data_test_controller.h b/apps/hardware_test/lcd_data_test_controller.h
index 9643068d9..4f662c021 100644
--- a/apps/hardware_test/lcd_data_test_controller.h
+++ b/apps/hardware_test/lcd_data_test_controller.h
@@ -7,6 +7,17 @@
 namespace HardwareTest {
 
 class LCDDataTestController : public ViewController {
+
+/* There are three types of tests, where a pattern is pushed to the screen and
+ * the number of invalid pixels then counted.
+ *   - Test 1: Tile the screen with color patches. Tiling increases the number
+ *   of border mistakes.
+ *   - Test 2: Push one color to the whole screen in one step. It shows errors
+ *   that appear on large and fast pushes.
+ *   - Test 3: Color the screen by alterning one pixel black and one pixel
+ *   white (maximal data difference), at maximal data writing speed.
+ * Tests 1 and 2 are done for a few different colors. */
+
 public:
   LCDDataTestController(Responder * parentResponder) :
     ViewController(parentResponder),