diff --git a/tools/viewer/Viewer.cpp b/tools/viewer/Viewer.cpp
index 9ea36a4..6d5905a 100644
--- a/tools/viewer/Viewer.cpp
+++ b/tools/viewer/Viewer.cpp
@@ -1181,6 +1181,23 @@
     switch (state) {
         case Window::kUp_InputState: {
             fGesture.touchEnd(castedOwner);
+#if defined(SK_BUILD_FOR_IOS)
+            // TODO: move IOS swipe detection higher up into the platform code
+            SkPoint dir;
+            if (fGesture.isFling(&dir)) {
+                // swiping left or right
+                if (SkTAbs(dir.fX) > SkTAbs(dir.fY)) {
+                    if (dir.fX < 0) {
+                        this->setCurrentSlide(fCurrentSlide < fSlides.count() - 1 ?
+                                              fCurrentSlide + 1 : 0);
+                    } else {
+                        this->setCurrentSlide(fCurrentSlide > 0 ?
+                                              fCurrentSlide - 1 : fSlides.count() - 1);
+                    }
+                }
+                fGesture.reset();
+            }
+#endif
             break;
         }
         case Window::kDown_InputState: {