diff --git a/Dockerfile b/Dockerfile
index 08910a6..6b57444 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,78 +1,103 @@
 FROM ubuntu:16.04
 
-#=======================
-# General Configuration
-#=======================
 ENV DEBIAN_FRONTEND noninteractive
-RUN apt-get update -y
-
-#=====================================
-# Install virtual display framebuffer
-#=====================================
-RUN apt-get install xvfb x11vnc -y
-
-#=========================================================
-# Install Windows Manager, Debian Menu, Numpy and Netstat
-# https://github.com/novnc/websockify/issues/77
-#=========================================================
-RUN apt-get install openbox menu python-numpy net-tools -y
-
-#====================
-# Install Supervisor
-#====================
-RUN apt-get install supervisor -y
 
 #=============
 # Set WORKDIR
 #=============
 WORKDIR /root
 
+#==================
+# General Packages
+#------------------
+# git
+#   Clone git repository
+# wget
+#   Network downloader
+# unzip
+#   Unzip zip file
+# curl
+#   Transfer data from or to a server
+# supervisor
+#   Process manager
+# openjdk-8-jdk
+#   Java
+# libqt5webkit5
+#   Web content engine (Fix issue in Android)
+#------------------
+#  NoVNC Packages
+#------------------
+# xvfb
+#   X virtual framebuffer
+# x11vnc
+#   VNC server for X display
+# openbox
+#   Windows manager
+# menu
+#   Debian menu
+# python-numpy
+#   Numpy, For faster performance: https://github.com/novnc/websockify/issues/77
+# net-tools
+#   Netstat
+#------------------
+#    KVM Package
+# for emulator x86
+# https://help.ubuntu.com/community/KVM/Installation
+#------------------
+# qemu-kvm
+# libvirt-bin
+# ubuntu-vm-builder
+# bridge-utils
+#==================
+RUN apt-get update && apt-get install -y \
+    git \
+    wget \
+    unzip \
+    curl \
+    supervisor \
+    openjdk-8-jdk \
+    libqt5webkit5 \
+    xvfb \
+    x11vnc \
+    openbox \
+    menu \
+    python-numpy \
+    net-tools \
+    qemu-kvm \
+    libvirt-bin \
+    ubuntu-vm-builder \
+    bridge-utils \
+ && rm -rf /var/lib/apt/lists/*
+
 #======================
 # Clone noVNC projects
 #======================
-RUN apt-get install git -y
-RUN git clone https://github.com/kanaka/noVNC.git && \
-    cd noVNC/utils && git clone https://github.com/kanaka/websockify websockify
+RUN git clone https://github.com/kanaka/noVNC.git \
+ && cd noVNC/utils && git clone https://github.com/kanaka/websockify websockify
 
-#==============
-# Install Java
-#==============
-RUN apt-get install openjdk-8-jdk -y
-ENV JAVA_HOME="/usr/lib/jvm/java-8-openjdk-amd64/jre"
-ENV PATH="${PATH}:${JAVA_HOME}/bin"
+#======================================
+# Install Android SDK and its packages
+#======================================
+ENV JAVA_HOME /usr/lib/jvm/java-8-openjdk-amd64/jre
+ENV PATH ${PATH}:${JAVA_HOME}/bin
 
-#=====================
-# Install Android SDK
-#=====================
-RUN apt-get install wget unzip libqt5webkit5 -y
-
-RUN wget https://dl.google.com/android/repository/tools_r25.2.3-linux.zip && \
-    unzip tools_r25.2.3-linux.zip && rm tools_r25.2.3-linux.zip
-ENV ANDROID_HOME="/root"
-ENV PATH="${PATH}:${ANDROID_HOME}/tools"
-
-#=====================================================
-# Install Platform-tools, Build-tools
-# To see list of available packages: android list sdk
-#=====================================================
-RUN echo y | android update sdk --no-ui --filter platform-tools,build-tools-25.0.2
-ENV PATH="${PATH}:${ANDROID_HOME}/platform-tools:${ANDROID_HOME}/build-tools"
+ENV SDK_VERSION=25.2.3 \
+    BUILD_TOOL=25.0.2 \
+    ANDROID_HOME=/root
+RUN wget -O android.zip https://dl.google.com/android/repository/tools_r${SDK_VERSION}-linux.zip \
+ && unzip android.zip && rm android.zip
+ENV PATH ${PATH}:${ANDROID_HOME}/tools
+RUN echo y | android update sdk --no-ui --filter platform-tools,build-tools-${BUILD_TOOL}
+ENV PATH ${PATH}:${ANDROID_HOME}/platform-tools:${ANDROID_HOME}/build-tools
 RUN mv ${ANDROID_HOME}/tools/emulator ${ANDROID_HOME}/tools/emulator.backup
 
 #====================================
 # Install latest nodejs, npm, appium
 #====================================
-RUN apt-get install curl -y
-RUN curl -sL https://deb.nodesource.com/setup_7.x | bash -
-RUN apt-get install nodejs -y
+RUN curl -sL https://deb.nodesource.com/setup_7.x | bash - \
+ && apt-get update && apt-get install -y nodejs && rm -rf /var/lib/apt/lists/*
 ENV APPIUM_VERSION 1.6.3
-RUN npm install -g appium@$APPIUM_VERSION
-
-#============================================================
-# Install KVM for emulator x86
-# Source: https://help.ubuntu.com/community/KVM/Installation
-#============================================================
-RUN apt-get install qemu-kvm libvirt-bin ubuntu-vm-builder bridge-utils -y
+RUN npm install -g appium@$APPIUM_VERSION && npm cache clean
 
 #================================================
 # noVNC Default Configurations
@@ -89,11 +114,15 @@ ENV DISPLAY=:0 \
     LOG_PATH=/var/log/supervisor
 RUN ln -s noVNC/vnc_auto.html noVNC/index.html
 
-#==============
+#===============
 # Expose Ports
-#==============
-EXPOSE 4723
-EXPOSE 6080
+#---------------
+# 4723
+#   appium port
+# 6080
+#   noVNC port
+#===============
+EXPOSE 4723 6080
 
 #==================
 # Add Browser APKs