minor fixes

android/app/src/main/java/com/reactnativenavigation/layouts/BottomTabsLayout.java

         super(activity);
         this.activity = activity;
         this.params = params;
-        screenStacks = new ScreenStack[(params.tabParams.size())];
+        screenStacks = new ScreenStack[params.tabParams.size()];
         createLayout();
     }
 
     }
 
     private void showInitialScreenStack() {
-        showStack(screenStacks[0]);
+        showStackAndUpdateStyle(screenStacks[0]);
     }
 
     @Override
     @Override
     public void setTopBarVisible(String screenInstanceId, boolean hidden, boolean animated) {
         for (int i = 0; i < bottomTabs.getItemsCount(); i++) {
-            screenStacks[i].setTopBarVisible(screenInstanceId, hidden, animated);
+            screenStacks[i].setScreenTopBarVisible(screenInstanceId, hidden, animated);
         }
     }
 
     @Override
     public void setTitleBarTitle(String screenInstanceId, String title) {
         for (int i = 0; i < bottomTabs.getItemsCount(); i++) {
-            screenStacks[i].setTitleBarTitle(screenInstanceId, title);
+            screenStacks[i].setScreenTitleBarTitle(screenInstanceId, title);
         }
     }
 
     @Override
     public void setTitleBarRightButtons(String screenInstanceId, String navigatorEventId, List<TitleBarButtonParams> titleBarButtons) {
         for (int i = 0; i < bottomTabs.getItemsCount(); i++) {
-            screenStacks[i].setTitleBarRightButtons(screenInstanceId, navigatorEventId, titleBarButtons);
+            screenStacks[i].setScreenTitleBarRightButtons(screenInstanceId, navigatorEventId, titleBarButtons);
         }
     }
 
     @Override
     public void setTitleBarLeftButton(String screenInstanceId, String navigatorEventId, TitleBarLeftButtonParams titleBarLeftButtonParams) {
         for (int i = 0; i < bottomTabs.getItemsCount(); i++) {
-            screenStacks[i].setTitleBarLeftButton(screenInstanceId, navigatorEventId, titleBarLeftButtonParams);
+            screenStacks[i].setScreenTitleBarLeftButton(screenInstanceId, navigatorEventId, titleBarLeftButtonParams);
         }
     }
 
         hideCurrentStack();
 
         ScreenStack newStack = screenStacks[position];
-        showStack(newStack);
+        showStackAndUpdateStyle(newStack);
         currentStackIndex = position;
 
         return true;
     }
 
-    private void showStack(ScreenStack newStack) {
+    private void showStackAndUpdateStyle(ScreenStack newStack) {
         newStack.setVisibility(VISIBLE);
         bottomTabs.setStyleFromScreen(newStack.getCurrentScreenStyleParams());
     }

android/app/src/main/java/com/reactnativenavigation/layouts/SingleScreenLayout.java

 
     @Override
     public void setTopBarVisible(String screenInstanceID, boolean visible, boolean animate) {
-        stack.setTopBarVisible(screenInstanceID, visible, animate);
+        stack.setScreenTopBarVisible(screenInstanceID, visible, animate);
     }
 
     @Override
     public void setTitleBarTitle(String screenInstanceId, String title) {
-        stack.setTitleBarTitle(screenInstanceId, title);
+        stack.setScreenTitleBarTitle(screenInstanceId, title);
     }
 
     @Override
     @Override
     public void setTitleBarRightButtons(String screenInstanceId, String navigatorEventId,
                                         List<TitleBarButtonParams> titleBarRightButtons) {
-        stack.setTitleBarRightButtons(screenInstanceId, navigatorEventId, titleBarRightButtons);
+        stack.setScreenTitleBarRightButtons(screenInstanceId, navigatorEventId, titleBarRightButtons);
     }
 
     @Override
     public void setTitleBarLeftButton(String screenInstanceId, String navigatorEventId, TitleBarLeftButtonParams titleBarLeftButtonParams) {
-        stack.setTitleBarLeftButton(screenInstanceId, navigatorEventId, titleBarLeftButtonParams);
+        stack.setScreenTitleBarLeftButton(screenInstanceId, navigatorEventId, titleBarLeftButtonParams);
     }
 }

android/app/src/main/java/com/reactnativenavigation/screens/ScreenStack.java

 import com.reactnativenavigation.params.ScreenStyleParams;
 import com.reactnativenavigation.params.TitleBarButtonParams;
 import com.reactnativenavigation.params.TitleBarLeftButtonParams;
+import com.reactnativenavigation.utils.Task;
 import com.reactnativenavigation.views.TitleBarBackButtonListener;
 
 import java.util.List;
 
 // TODO there's really no reason for ScreenStack to extend FrameLayout. All screens can be added to parent.
 public class ScreenStack extends FrameLayout implements TitleBarBackButtonListener {
+
     private final AppCompatActivity activity;
     private Stack<Screen> stack = new Stack<>();
 
 
     public void pop() {
         if (!canPop()) {
-            throw new RuntimeException("Can't pop ScreenStack of size " + getStackSize());
+            return;
         }
 
         Screen toRemove = stack.pop();
         return getStackSize() > 1;
     }
 
-    public void setTopBarVisible(String screenInstanceId, boolean visible, boolean animate) {
-        Screen screen = findScreenByScreenInstanceId(screenInstanceId);
-        if (screen != null) {
-            screen.setTopBarVisible(visible, animate);
-        }
-    }
-
-    public Screen findScreenByScreenInstanceId(String screenInstanceId) {
-        if (stack.isEmpty()) {
-            return null;
-        }
-
-        for (Screen screen : stack) {
-            if (screen.getScreenInstanceId().equals(screenInstanceId)) {
-                return screen;
+    public void setScreenTopBarVisible(String screenInstanceId, final boolean visible, final boolean animate) {
+        performOnScreen(screenInstanceId, new Task<Screen>() {
+            @Override
+            public void run(Screen param) {
+                param.setTopBarVisible(visible, animate);
             }
-        }
-
-        return null;
+        });
     }
 
-    public void setTitleBarTitle(String screenInstanceId, String title) {
-        Screen screen = findScreenByScreenInstanceId(screenInstanceId);
-        if (screen != null) {
-            screen.setTitleBarTitle(title);
-        }
+    public void setScreenTitleBarTitle(String screenInstanceId, final String title) {
+        performOnScreen(screenInstanceId, new Task<Screen>() {
+            @Override
+            public void run(Screen param) {
+                param.setTitleBarTitle(title);
+            }
+        });
     }
 
-    public void setTitleBarRightButtons(String screenInstanceId, String navigatorEventId, List<TitleBarButtonParams> titleBarButtons) {
-        Screen screen = findScreenByScreenInstanceId(screenInstanceId);
-        if (screen != null) {
-            screen.setTitleBarRightButtons(navigatorEventId, titleBarButtons);
-        }
+    public void setScreenTitleBarRightButtons(String screenInstanceId, final String navigatorEventId, final List<TitleBarButtonParams> titleBarButtons) {
+        performOnScreen(screenInstanceId, new Task<Screen>() {
+            @Override
+            public void run(Screen param) {
+                param.setTitleBarRightButtons(navigatorEventId, titleBarButtons);
+            }
+        });
     }
 
-    public void setTitleBarLeftButton(String screenInstanceId, String navigatorEventId, TitleBarLeftButtonParams titleBarLeftButtonParams) {
-        Screen screen = findScreenByScreenInstanceId(screenInstanceId);
-        if (screen != null) {
-            screen.setTitleBarLeftButton(navigatorEventId, this, titleBarLeftButtonParams);
-        }
+    public void setScreenTitleBarLeftButton(String screenInstanceId, final String navigatorEventId, final TitleBarLeftButtonParams titleBarLeftButtonParams) {
+        performOnScreen(screenInstanceId, new Task<Screen>() {
+            @Override
+            public void run(Screen param) {
+                param.setTitleBarLeftButton(navigatorEventId, ScreenStack.this, titleBarLeftButtonParams);
+            }
+        });
     }
 
     @Override
         }
     }
 
-    public void preventUnmountOnDetachedFromWindow() {
-        for (Screen screen : stack) {
-            screen.preventUnmountOnDetachedFromWindow();
-        }
+    public ScreenStyleParams getCurrentScreenStyleParams() {
+        return stack.peek().getStyleParams();
     }
 
-    public void ensureUnmountOnDetachedFromWindow() {
-        for (Screen screen : stack) {
-            screen.ensureUnmountOnDetachedFromWindow();
+    private void performOnScreen(String screenInstanceId, Task<Screen> task) {
+        if (stack.isEmpty()) {
+            return;
         }
-    }
 
-    public void preventMountAfterReatachedToWindow() {
         for (Screen screen : stack) {
-            screen.preventMountAfterReattachedToWindow();
+            if (screen.getScreenInstanceId().equals(screenInstanceId)) {
+                task.run(screen);
+                return;
+            }
         }
     }
-
-    public ScreenStyleParams getCurrentScreenStyleParams() {
-        return stack.peek().getStyleParams();
-    }
 }

android/app/src/main/java/com/reactnativenavigation/utils/Task.java

+package com.reactnativenavigation.utils;
+
+public interface Task<T> {
+    void run(T param);
+}

example-redux/src/app.js

   startApp(root) {
     switch (root) {
       case 'login':
+        //Navigation.startSingleScreenApp({
+        //  screen: {
+        //    screen: 'example.LoginScreen',
+        //    title: 'Login',
+        //    navigatorStyle: {}
+        //  },
+        //  passProps: {
+        //    str: 'This is a prop passed in \'startSingleScreenApp()\'!',
+        //    obj: {
+        //      str: 'This is a prop passed in an object!',
+        //      arr: [
+        //        {
+        //          str: 'This is a prop in an object in an array in an object!'
+        //        }
+        //      ],
+        //      arr2: [
+        //        [
+        //          'array of strings',
+        //          'with two strings'
+        //        ],
+        //        [
+        //          1, 2, 3
+        //        ]
+        //      ]
+        //    },
+        //    num: 1234
+        //  }
+        //});
         Navigation.startSingleScreenApp({
           screen: {
-            screen: 'example.LoginScreen',
+            screen: 'example.FirstTabScreen',
             title: 'Login',
+            topTabs: [
+              {
+                screenId: 'example.ListScreen',
+                title: 'Tab1'
+              },
+              {
+                screenId: 'example.PushedScreen',
+                title: 'Tab2'
+              },
+              {
+                screenId: 'example.PushedScreen',
+                title: 'Tab3'
+              },
+              {
+                screenId: 'example.FirstTabScreen',
+                title: 'Tab4'
+              }
+            ],
             navigatorStyle: {}
           },
           passProps: {

example-redux/src/screens/PushedScreen.js

   };
 
   static navigatorButtons = {
-    leftButton:
-      {
-        id: 'back',
-        color: '#00ff00'
-      }
+    leftButton: {
+      id: 'back',
+      color: '#00ff00'
+    }
   };
 
   constructor(props) {
 
   onPushPress() {
     this.props.navigator.push({
-      title: "More",
-      screen: "example.PushedScreen",
+      title: "List",
+      screen: "example.ListScreen",
       passProps: {
         passed: 'This is a prop passed in \'navigator.push()\'!',
         obj: {