diff --git a/.gitignore b/.gitignore
index 11cae614d1ca..d97915fc5f6e 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,3 @@
 dist
-node_modulesi
+node_modules/
 *.log
diff --git a/src/client/ui/admin.js b/src/client/ui/admin.js
index cee65184de56..da572160c9ef 100644
--- a/src/client/ui/admin.js
+++ b/src/client/ui/admin.js
@@ -40,9 +40,9 @@ export function getControls(data) {
 
 export function getIframe(data) {
   const iframeStyle = {
-    width: '100%',
+    width: 'calc(100% - 10px)', // minus manual resizer width
     height: '100%',
-    border: '0',
+    border: '2px solid #e0e0e0',
   };
 
   // We need to send dataId via queryString
diff --git a/src/client/ui/layout.js b/src/client/ui/layout.js
index d4a3e0469f01..540e828ec9f7 100644
--- a/src/client/ui/layout.js
+++ b/src/client/ui/layout.js
@@ -1,12 +1,90 @@
 import React from 'react';
+import ReactDOM from 'react-dom';
+import SizeButton from './size-button';
+
+const sizes = {
+  iphone4: {
+    width: 320,
+    height: 480,
+  },
+  samsungS5: {
+    width: 360,
+    height: 640,
+  },
+  iphone6: {
+    width: 375,
+    height: 667,
+  },
+};
 
 class Layout extends React.Component {
+  constructor(props) {
+    super(props);
+
+    this.state = {
+      isControlOpen: true,
+      isActionLoggerOpen: true,
+      isIframeCoverHidden: true,
+      viewportHeight: 500,
+      viewportWidth: 400,
+      origClientX: 0,
+      dragging: false,
+    };
+
+    this.toggleControls = this.toggleControls.bind(this);
+    this.toggleActionLogger = this.toggleActionLogger.bind(this);
+    this.toggleIframeCover = this.toggleIframeCover.bind(this);
+
+    this.updateHeight = this.updateHeight.bind(this);
+    this.updateViewportWidth = this.updateViewportWidth.bind(this);
+    this.updateViewportHeight = this.updateViewportHeight.bind(this);
+    this.updateOrigClientX = this.updateOrigClientX.bind(this);
+
+    this.handleOnMouseDownResizer = this.handleOnMouseDownResizer.bind(this);
+    this.handleOnMouseMove = this.handleOnMouseMove.bind(this);
+    this.handleOnMouseUp = this.handleOnMouseUp.bind(this);
+    this.handleOnChangeWidthInput = this.handleOnChangeWidthInput.bind(this);
+    this.handleOnChangeHeightInput = this.handleOnChangeHeightInput.bind(this);
+    this.handleOnClickSizeBtn = this.handleOnClickSizeBtn.bind(this);
+  }
+
   componentWillMount() {
     this.updateHeight();
   }
 
   componentDidMount() {
-    window.addEventListener('resize', this.updateHeight.bind(this));
+    window.addEventListener('mousemove', this.handleOnMouseMove);
+    window.addEventListener('mouseup', this.handleOnMouseUp);
+    window.addEventListener('resize', this.updateHeight);
+  }
+
+  componentWillUnmount() {
+    window.removeEventListener('mousemove', this.handleOnMouseMove);
+    window.removeEventListener('mouseup', this.handleOnMouseUp);
+    window.removeEventListener('resize', this.updateHeight);
+  }
+
+  updateViewportWidth(viewportWidth) {
+    /*
+    // so far i didn't any anomalies
+    // can be removed if there's no issue
+    const resizer = this.refs.manualResizer;
+    const resizerEl = ReactDOM.findDOMNode(resizer);
+    const currentXPos = resizerEl.getBoundingClientRect().left;
+    this.updateOrigClientX(currentXPos);
+    */
+
+    this.setState({
+      viewportWidth,
+    });
+
+    return;
+  }
+
+  updateViewportHeight(viewportHeight) {
+    this.setState({
+      viewportHeight,
+    });
   }
 
   updateHeight() {
@@ -16,43 +94,246 @@ class Layout extends React.Component {
     this.setState({ height });
   }
 
+  updateOrigClientX(coord) {
+    this.setState({
+      origClientX: coord,
+    });
+  }
+
+  toggleControls() {
+    this.setState({
+      isControlOpen: !this.state.isControlOpen,
+    });
+  }
+
+  toggleActionLogger() {
+    this.setState({
+      isActionLoggerOpen: !this.state.isActionLoggerOpen,
+    });
+  }
+
+  toggleIframeCover() {
+    this.setState({
+      isIframeCoverHidden: !this.state.isIframeCoverHidden,
+    });
+  }
+
+  handleOnMouseDownResizer(event) {
+    this.updateOrigClientX(event.clientX);
+
+    // make cover visible so that mouse pointer doesn't
+    // go into iframe
+    this.toggleIframeCover();
+
+    this.setState({
+      dragging: true,
+    });
+  }
+
+  handleOnMouseMove(event) {
+    if (this.state.dragging) {
+      const currentPos = event.clientX;
+      const origPos = parseInt(this.state.origClientX);
+      const diffPos = currentPos - origPos;
+      const currentViewportWidth = parseInt(this.state.viewportWidth);
+      const newViewportWidth = currentViewportWidth + diffPos;
+
+      this.updateOrigClientX(currentPos);
+      this.updateViewportWidth(newViewportWidth);
+    }
+  }
+
+  handleOnMouseUp() {
+    if (this.state.dragging) {
+      // hide iframe cover to enable iframe interaction
+      this.toggleIframeCover();
+
+      this.setState({
+        dragging: false,
+      });
+    }
+  }
+
+  handleOnChangeWidthInput(event) {
+    this.updateViewportWidth(event.target.value);
+  }
+
+  handleOnChangeHeightInput(event) {
+    this.updateViewportHeight(event.target.value);
+  }
+
+  handleOnClickSizeBtn(size) {
+    const height = sizes[size].height;
+    const width = sizes[size].width;
+
+    this.updateViewportHeight(height);
+    this.updateViewportWidth(width);
+  }
+
   render() {
-    const { controls, preview, actionLogger } = this.props;
-    const { height } = this.state;
+    const {
+      controls,
+      preview,
+      actionLogger,
+    } = this.props;
+
+    const {
+      height,
+      viewportWidth,
+      viewportHeight,
+      isControlOpen,
+      isActionLoggerOpen,
+      isIframeCoverHidden,
+    } = this.state;
 
     const rootStyles = {
       height,
       padding: 8,
       backgroundColor: '#F7F7F7',
     };
-    const controlsStyle = {
+
+    let controlsStyle = {
+      position: 'fixed',
+      top: 0,
+      left: -240,
+      bottom: 0,
       width: 240,
-      float: 'left',
-      height: '100%',
       overflowY: 'auto',
     };
 
-    const actionStyle = {
+    let actionStyle = {
+      position: 'fixed',
+      bottom: -150,
+      width: '100%',
       height: 150,
-      marginLeft: 250,
     };
 
-    const previewStyle = {
-      height: height - actionStyle.height - 25,
-      marginLeft: 250,
+    let previewStyle = {
+      height: height - 16,
       border: '1px solid #ECECEC',
       borderRadius: 4,
       padding: 5,
       backgroundColor: '#FFF',
     };
 
+    const toggleStyle = {
+      display: 'block',
+      height: '36px',
+      overflow: 'hidden',
+    };
+
+    const iframeStyle = {
+      width: `${viewportWidth}px`,
+      height: `${viewportHeight}px`,
+      margin: '0 auto',
+    };
+
+    let iframeCoverStyle = {
+      display: 'initial',
+      position: 'fixed',
+      top: 0,
+      right: 0,
+      bottom: 0,
+      left: 0,
+      zIndex: 200,
+    };
+
+    const manualResizerStyle = {
+      width: '5px',
+      height: '100%',
+      backgroundColor: 'red',
+      borderTop: '2px solid red',
+      borderBottom: '2px solid red',
+      display: 'inline-block',
+      cursor: 'col-resize',
+    };
+
+    if (isControlOpen) {
+      controlsStyle = {
+        ...controlsStyle,
+        left: 0,
+      };
+
+      actionStyle = {
+        ...actionStyle,
+        marginLeft: 250,
+      };
+
+      previewStyle = {
+        ...previewStyle,
+        marginLeft: 250,
+      };
+    }
+
+    if (isActionLoggerOpen) {
+      actionStyle = {
+        ...actionStyle,
+        bottom: 0,
+      };
+
+      previewStyle = {
+        ...previewStyle,
+        height: height - actionStyle.height - 16,
+      };
+    }
+
+    if (isIframeCoverHidden) {
+      iframeCoverStyle = {
+        ...iframeCoverStyle,
+        display: 'none',
+      };
+    }
+
     return (
       <div style={rootStyles}>
         <div style={controlsStyle}>
           {controls}
         </div>
         <div style={previewStyle}>
-          {preview}
+          <div style={toggleStyle}>
+            <input
+              type="number"
+              value={viewportWidth}
+              placeholder="width"
+              onChange={this.handleOnChangeWidthInput}
+            />
+            <input
+              type="number"
+              value={viewportHeight}
+              placeholder="height"
+              onChange={this.handleOnChangeHeightInput}
+            />
+            <button onClick={this.toggleControls}>
+              toggle controls
+            </button>
+            <button onClick={this.toggleActionLogger}>
+              toggle action
+            </button>
+            <SizeButton
+              type="iphone4"
+              label="iPhone 4"
+              onClick={this.handleOnClickSizeBtn}
+            />
+            <SizeButton
+              type="samsungS5"
+              label="Samsung S5"
+              onClick={this.handleOnClickSizeBtn}
+            />
+            <SizeButton
+              type="iphone6"
+              label="iPhone 6"
+              onClick={this.handleOnClickSizeBtn}
+            />
+          </div>
+          <div style={iframeCoverStyle}></div>
+          <div style={iframeStyle}>
+            {preview}
+            <div
+              ref="manualResizer"
+              style={manualResizerStyle}
+              onMouseDown={this.handleOnMouseDownResizer}
+            ></div>
+          </div>
         </div>
         <div style={actionStyle}>
           {actionLogger}
diff --git a/src/client/ui/size-button.js b/src/client/ui/size-button.js
new file mode 100644
index 000000000000..0cbe57abe6a7
--- /dev/null
+++ b/src/client/ui/size-button.js
@@ -0,0 +1,27 @@
+import React, { PropTypes } from 'react';
+
+/**
+ * proxy component
+ */
+
+const propTypes = {
+  type: PropTypes.string.isRequired,
+  label: PropTypes.string.isRequired,
+  onClick: PropTypes.func.isRequired,
+};
+
+const SizeButton = ({
+  type,
+  label,
+  onClick,
+}) => {
+  const onClickBtn = () => (onClick(type));
+
+  return (
+    <button onClick={onClickBtn}>{label}</button>
+  );
+};
+
+SizeButton.propTypes = propTypes;
+
+export default SizeButton;