diff --git a/ReactAndroid/src/androidTest/java/com/facebook/react/tests/CatalystUIManagerTestCase.java b/ReactAndroid/src/androidTest/java/com/facebook/react/tests/CatalystUIManagerTestCase.java
new file mode 100644
index 0000000000..e8c16f8924
--- /dev/null
+++ b/ReactAndroid/src/androidTest/java/com/facebook/react/tests/CatalystUIManagerTestCase.java
@@ -0,0 +1,250 @@
+/**
+ * Copyright (c) 2013-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ */
+
+package com.facebook.react.tests;
+
+import java.util.Arrays;
+import java.util.List;
+
+import android.util.DisplayMetrics;
+import android.view.View;
+import android.view.ViewGroup;
+import android.widget.FrameLayout;
+import android.widget.TextView;
+
+import com.facebook.react.ReactRootView;
+import com.facebook.react.bridge.JavaScriptModule;
+import com.facebook.react.bridge.UiThreadUtil;
+import com.facebook.react.modules.systeminfo.AndroidInfoModule;
+import com.facebook.react.uimanager.PixelUtil;
+import com.facebook.react.uimanager.UIImplementation;
+import com.facebook.react.uimanager.UIManagerModule;
+import com.facebook.react.uimanager.ViewManager;
+import com.facebook.react.views.text.ReactRawTextManager;
+import com.facebook.react.views.text.ReactTextViewManager;
+import com.facebook.react.views.view.ReactViewManager;
+import com.facebook.react.testing.ReactIntegrationTestCase;
+import com.facebook.react.testing.ReactTestHelper;
+
+/**
+ * Test case for basic {@link UIManagerModule} functionality.
+ */
+public class CatalystUIManagerTestCase extends ReactIntegrationTestCase {
+  private interface UIManagerTestModule extends JavaScriptModule {
+    void renderFlexTestApplication(int rootTag);
+    void renderFlexWithTextApplication(int rootTag);
+    void renderAbsolutePositionTestApplication(int rootTag);
+    void renderAbsolutePositionBottomRightTestApplication(int rootTag);
+    void renderCenteredTextViewTestApplication(int rootTag, String text);
+    void renderUpdatePositionInListTestApplication(int rootTag);
+    void flushUpdatePositionInList();
+  }
+
+  private UIManagerTestModule jsModule;
+  private UIManagerModule uiManager;
+
+  private int inPixelRounded(int val) {
+    return Math.round(PixelUtil.toPixelFromDIP(val));
+  }
+
+  private boolean isWithinRange(float value, float lower, float upper) {
+    return value >= lower && value <= upper;
+  }
+
+  private ReactRootView createRootView() {
+    ReactRootView rootView = new ReactRootView(getContext());
+    final DisplayMetrics metrics = getContext().getResources().getDisplayMetrics();
+    rootView.setLayoutParams(
+        new FrameLayout.LayoutParams(metrics.widthPixels, metrics.heightPixels));
+    uiManager.addMeasuredRootView(rootView);
+    // We add the root view by posting to the main thread so wait for that to complete so that the
+    // root view tag is added to the view
+    waitForIdleSync();
+    return rootView;
+  }
+
+  @Override
+  protected void setUp() throws Exception {
+    super.setUp();
+
+    List<ViewManager> viewManagers = Arrays.<ViewManager>asList(
+        new ReactViewManager(),
+        new ReactTextViewManager(),
+        new ReactRawTextManager());
+    uiManager = new UIManagerModule(
+        getContext(),
+        viewManagers,
+        new UIImplementation(getContext(), viewManagers));
+    UiThreadUtil.runOnUiThread(new Runnable() {
+      @Override
+      public void run() {
+        uiManager.onHostResume();
+      }
+    });
+    waitForIdleSync();
+
+    jsModule = ReactTestHelper.catalystInstanceBuilder(this)
+        .addNativeModule(uiManager)
+        .addNativeModule(new AndroidInfoModule())
+        .addJSModule(UIManagerTestModule.class)
+        .build()
+        .getJSModule(UIManagerTestModule.class);
+  }
+
+  public void testFlexUIRendered() {
+    FrameLayout rootView = createRootView();
+    jsModule.renderFlexTestApplication(rootView.getId());
+    waitForBridgeAndUIIdle();
+
+    assertEquals(1, rootView.getChildCount());
+
+    ViewGroup container = getViewByTestId(rootView, "container");
+    assertEquals(inPixelRounded(200), container.getWidth());
+    assertEquals(inPixelRounded(200), container.getHeight());
+    assertEquals(2, container.getChildCount());
+
+    View child0 = container.getChildAt(0);
+    assertEquals(inPixelRounded(100), child0.getWidth());
+    assertEquals(inPixelRounded(200), child0.getHeight());
+
+    View child1 = container.getChildAt(1);
+    assertEquals(inPixelRounded(100), child1.getWidth());
+    assertEquals(inPixelRounded(200), child1.getHeight());
+  }
+
+  public void testFlexWithTextViews() {
+    FrameLayout rootView = createRootView();
+    jsModule.renderFlexWithTextApplication(rootView.getId());
+    waitForBridgeAndUIIdle();
+
+    assertEquals(1, rootView.getChildCount());
+
+    ViewGroup container = getViewByTestId(rootView, "container");
+    assertEquals(inPixelRounded(300), container.getHeight());
+    assertEquals(1, container.getChildCount());
+
+    ViewGroup row = (ViewGroup) container.getChildAt(0);
+    assertEquals(inPixelRounded(300), row.getHeight());
+    assertEquals(2, row.getChildCount());
+
+    // Text measurement adds padding that isn't completely dependent on density so we can't easily
+    // get an exact value here
+    float approximateExpectedTextHeight = inPixelRounded(19);
+    View leftText = row.getChildAt(0);
+    assertTrue(
+        isWithinRange(
+            leftText.getHeight(),
+            approximateExpectedTextHeight - PixelUtil.toPixelFromDIP(1),
+            approximateExpectedTextHeight + PixelUtil.toPixelFromDIP(1)));
+    assertEquals(row.getWidth() / 2 - inPixelRounded(20), leftText.getWidth());
+    assertEquals(inPixelRounded(290), (leftText.getTop() + leftText.getHeight()));
+
+    View rightText = row.getChildAt(1);
+    assertTrue(
+        isWithinRange(
+            rightText.getHeight(),
+            approximateExpectedTextHeight - PixelUtil.toPixelFromDIP(1),
+            approximateExpectedTextHeight + PixelUtil.toPixelFromDIP(1)));
+    assertEquals(leftText.getWidth(), rightText.getWidth());
+    assertEquals(leftText.getTop(), rightText.getTop());
+    assertEquals(leftText.getWidth() + inPixelRounded(30), rightText.getLeft());
+  }
+
+  public void testAbsolutePositionUIRendered() {
+    FrameLayout rootView = createRootView();
+    jsModule.renderAbsolutePositionTestApplication(rootView.getId());
+    waitForBridgeAndUIIdle();
+
+    assertEquals(1, rootView.getChildCount());
+
+    View absoluteView = getViewByTestId(rootView, "absolute");
+    assertEquals(inPixelRounded(50), absoluteView.getWidth());
+    assertEquals(inPixelRounded(60), absoluteView.getHeight());
+    assertEquals(inPixelRounded(10), absoluteView.getLeft());
+    assertEquals(inPixelRounded(15), absoluteView.getTop());
+  }
+
+  public void testUpdatePositionInList() {
+    FrameLayout rootView = createRootView();
+    jsModule.renderUpdatePositionInListTestApplication(rootView.getId());
+    waitForBridgeAndUIIdle();
+
+    ViewGroup containerView = getViewByTestId(rootView, "container");
+    View c0 = containerView.getChildAt(0);
+    View c1 = containerView.getChildAt(1);
+    View c2 = containerView.getChildAt(2);
+
+    assertEquals(inPixelRounded(10), c0.getHeight());
+    assertEquals(inPixelRounded(0), c0.getTop());
+    assertEquals(inPixelRounded(10), c1.getHeight());
+    assertEquals(inPixelRounded(10), c1.getTop());
+    assertEquals(inPixelRounded(10), c2.getHeight());
+    assertEquals(inPixelRounded(20), c2.getTop());
+
+    // Let's make the second elements 50px height instead of 10px
+    jsModule.flushUpdatePositionInList();
+    waitForBridgeAndUIIdle();
+
+    assertEquals(inPixelRounded(10), c0.getHeight());
+    assertEquals(inPixelRounded(0), c0.getTop());
+    assertEquals(inPixelRounded(50), c1.getHeight());
+    assertEquals(inPixelRounded(10), c1.getTop());
+    assertEquals(inPixelRounded(10), c2.getHeight());
+    assertEquals(inPixelRounded(60), c2.getTop());
+  }
+
+  public void testAbsolutePositionBottomRightUIRendered() {
+    FrameLayout rootView = createRootView();
+    jsModule.renderAbsolutePositionBottomRightTestApplication(rootView.getId());
+    waitForBridgeAndUIIdle();
+
+    assertEquals(1, rootView.getChildCount());
+
+    ViewGroup containerView = getViewByTestId(rootView, "container");
+    View absoluteView = containerView.getChildAt(0);
+
+    assertEquals(inPixelRounded(50), absoluteView.getWidth());
+    assertEquals(inPixelRounded(60), absoluteView.getHeight());
+    assertEquals(inPixelRounded(100 - 50 - 10), Math.round(absoluteView.getLeft()));
+    assertEquals(inPixelRounded(100 - 60 - 15), Math.round(absoluteView.getTop()));
+  }
+
+  public void _testCenteredText(String text) {
+    ReactRootView rootView = new ReactRootView(getContext());
+    int rootTag = uiManager.addMeasuredRootView(rootView);
+
+    jsModule.renderCenteredTextViewTestApplication(rootTag, text);
+    waitForBridgeAndUIIdle();
+
+    TextView textView = getViewByTestId(rootView, "text");
+
+    // text view should be centered
+    String msg = "text `" + text + "` is not centered";
+    assertTrue(msg, textView.getLeft() > 0.1);
+    assertTrue(msg, textView.getTop() > 0.1);
+    assertEquals(
+        msg,
+        (int) Math.ceil((inPixelRounded(200) - textView.getWidth()) * 0.5f),
+        textView.getLeft());
+    assertEquals(
+        msg,
+        (int) Math.ceil((inPixelRounded(100) - textView.getHeight()) * 0.5f),
+        textView.getTop());
+  }
+
+  public void testCenteredTextCases() {
+    String[] cases = new String[] {
+      "test",
+      "with whitespace",
+    };
+    for (String text : cases) {
+      _testCenteredText(text);
+    }
+  }
+}
diff --git a/ReactAndroid/src/androidTest/js/TestBundle.js b/ReactAndroid/src/androidTest/js/TestBundle.js
index b506f40ad5..960c485a37 100644
--- a/ReactAndroid/src/androidTest/js/TestBundle.js
+++ b/ReactAndroid/src/androidTest/js/TestBundle.js
@@ -18,6 +18,7 @@ require('ViewRenderingTestModule');
 require('TestJavaToJSArgumentsModule');
 require('TestJSLocaleModule');
 require('TestJSToJavaParametersModule');
+require('UIManagerTestModule');
 
 require('CatalystRootViewTestModule');
 require('DatePickerDialogTestModule');
diff --git a/ReactAndroid/src/androidTest/js/UIManagerTestModule.js b/ReactAndroid/src/androidTest/js/UIManagerTestModule.js
new file mode 100644
index 0000000000..f8896a12c7
--- /dev/null
+++ b/ReactAndroid/src/androidTest/js/UIManagerTestModule.js
@@ -0,0 +1,202 @@
+/**
+ * Copyright (c) 2013-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ *
+ * @providesModule UIManagerTestModule
+ */
+
+'use strict';
+
+var BatchedBridge = require('BatchedBridge');
+var React = require('React');
+var StyleSheet = require('StyleSheet');
+var View = require('View');
+var Text = require('Text');
+
+var renderApplication = require('renderApplication');
+
+var FlexTestApp = React.createClass({
+  _styles: StyleSheet.create({
+    container: {
+      width: 200,
+      height: 200,
+      flexDirection: 'row',
+    },
+    child: {
+      flex: 1,
+    },
+    absolute: {
+      position: 'absolute',
+      top: 15,
+      left: 10,
+      width: 50,
+      height: 60,
+    }
+  }),
+  render: function() {
+    return (
+      <View style={this._styles.container} testID="container" collapsable={false}>
+        <View style={[this._styles.child, {backgroundColor: '#ff0000'}]} collapsable={false}/>
+        <View style={[this._styles.child, {backgroundColor: '#0000ff'}]} collapsable={false}/>
+      </View>
+    );
+  }
+});
+
+var FlexWithText = React.createClass({
+  _styles: StyleSheet.create({
+    container: {
+      flexDirection: 'column',
+      margin: 20,
+    },
+    row: {
+      flexDirection: 'row',
+      alignItems: 'flex-end',
+      height: 300,
+    },
+    inner: {
+      flex: 1,
+      margin: 10,
+    },
+  }),
+  render: function() {
+    return (
+      <View style={this._styles.container} testID="container" collapsable={false}>
+        <View style={this._styles.row} collapsable={false}>
+          <Text style={this._styles.inner}>Hello</Text>
+          <Text style={this._styles.inner}>World</Text>
+        </View>
+      </View>
+    );
+  }
+});
+
+var AbsolutePositionTestApp = React.createClass({
+  _styles: StyleSheet.create({
+    absolute: {
+      position: 'absolute',
+      top: 15,
+      left: 10,
+      width: 50,
+      height: 60,
+    }
+  }),
+  render: function() {
+    return <View style={this._styles.absolute} testID="absolute" collapsable={false}/>;
+  }
+});
+
+var AbsolutePositionBottomRightTestApp = React.createClass({
+  _styles: StyleSheet.create({
+    container: {
+      width: 100,
+      height: 100,
+    },
+    absolute: {
+      position: 'absolute',
+      bottom: 15,
+      right: 10,
+      width: 50,
+      height: 60,
+    }
+  }),
+  render: function() {
+    return (
+      <View style={this._styles.container} testID="container" collapsable={false}>
+        <View style={this._styles.absolute} collapsable={false}/>
+      </View>
+    );
+  }
+});
+
+var CenteredTextView = React.createClass({
+  _styles: StyleSheet.create({
+    parent: {
+      width: 200,
+      height: 100,
+      backgroundColor: '#aa3311',
+      flex: 1,
+      justifyContent: 'center',
+      alignItems: 'center',
+    },
+    text: {
+      fontSize: 15,
+      color: '#672831',
+    },
+  }),
+  render: function() {
+    return (
+      <View collapsable={false}>
+        <View style={this._styles.parent} collapsable={false}>
+          <Text style={this._styles.text} testID="text">{this.props.text}</Text>
+        </View>
+      </View>
+    );
+  }
+});
+
+var flushUpdatePositionInList = null;
+var UpdatePositionInListTestApp = React.createClass({
+  _styles: StyleSheet.create({
+    element: {
+      height: 10,
+    },
+    active: {
+      height: 50,
+    }
+  }),
+  getInitialState: function() {
+    flushUpdatePositionInList = () => this.setState({ active: true });
+    return { active: false };
+  },
+  render: function() {
+    return (
+      <View collapsable={false} testID="container">
+        <View style={this._styles.element} collapsable={false} />
+        <View
+          style={[
+            this._styles.element,
+            this.state.active && this._styles.active,
+          ]}
+          collapsable={false}
+        />
+        <View style={this._styles.element} collapsable={false}/>
+      </View>
+    );
+  }
+});
+
+var UIManagerTestModule = {
+  renderFlexTestApplication: function(rootTag) {
+    renderApplication(FlexTestApp, {}, rootTag);
+  },
+  renderFlexWithTextApplication: function(rootTag) {
+    renderApplication(FlexWithText, {}, rootTag);
+  },
+  renderAbsolutePositionBottomRightTestApplication: function(rootTag) {
+    renderApplication(AbsolutePositionBottomRightTestApp, {}, rootTag);
+  },
+  renderAbsolutePositionTestApplication: function(rootTag) {
+    renderApplication(AbsolutePositionTestApp, {}, rootTag);
+  },
+  renderCenteredTextViewTestApplication: function(rootTag, text) {
+    renderApplication(CenteredTextView, {text: text}, rootTag);
+  },
+  renderUpdatePositionInListTestApplication: function(rootTag) {
+    renderApplication(UpdatePositionInListTestApp, {}, rootTag);
+  },
+  flushUpdatePositionInList: function() {
+    flushUpdatePositionInList();
+  }
+};
+
+BatchedBridge.registerCallableModule(
+  'UIManagerTestModule',
+  UIManagerTestModule
+);
+
+module.exports = UIManagerTestModule;