update README

README.md

+# UNDER HEAVY DEVELOPMENT for v1.0-beta
+
+rough design document is [here](https://github.com/RocketChat/Rocket.Chat.Android/blob/doc/README.md)
+
+
+[![Circle CI](https://circleci.com/gh/RocketChat/Rocket.Chat.Android/tree/develop2.svg?style=shield)](https://circleci.com/gh/RocketChat/Rocket.Chat.Android/tree/develop2)
+
 # Rocket.Chat.Android
-Rocket.Chat Native Android Application
+Rocket.Chat Native Android Application.
+
+![screenshots](https://cloud.githubusercontent.com/assets/11763113/11993320/ccdcf296-aa72-11e5-9950-e08f7a280516.png)
+
+*Warning: This app is not production ready. It is under heavy development and any contributions are welcome.*
+
+
+## How to build
+
+Retrolambda needs java8 to be installed on your system
+```
+export ANDROID_HOME=/path/to/android/sdk
+
+git clone https://github.com/RocketChat/Rocket.Chat.Android.git
+cd Rocket.Chat.Android
+
+echo "sdk.dir="$ANDROID_HOME > local.properties
+
+cp app/fabric.properties.sample app/fabric.properties
+
+./gradlew assembleDebug
+```