Update README.md

README.md

@@ -2,5 +2,40 @@
 
 A easy way to achieve a ripple effect on you flutter app.
 
+<img src="https://github.com/ericdallo/ripple_effect/blob/assets/ripple_effect.gif" width="240">
+
 ## Usage
 
+First you need to wrap your page/Scaffold with the `RipplePage` widget, the ripple efect will growth until this widget. Then 
+wrap with the `RippleEffect` where the animation should begin. When the animation should begin, call the `RippleEffect.start` method passing you callback method(often navigate to other page).
+
+The `RipplePage` and `RippleEffect` widgets need their `GlobalKey`s respectively to work.
+
+## Example
+
+```dart
+class Stateless extends StatelessWidget {
+  final pageKey = RipplePage.createGlobalKey();
+  final effectKey = RippleEffect.createGlobalKey();
+  
+  @override
+  Widget build(BuildContext context) {
+    return RipplePage(
+      child: Scaffold(
+        body: Center(),
+        floatingActionButton: RippleEffect(
+          pageKey: pageKey,
+          effectKey: effectKey,
+          color: Colors.blue,
+          child: FloatingActionButton(
+            backgroundColor: Colors.blue,
+            onPressed: () =>
+                 RippleEffect.start(effectKey, () => toNextPage(context)),
+            child: Icon(Icons.arrow_back),
+          ),
+        )
+      ),
+    );
+  }
+}
+```