README.md in frontkick-0.1.0 vs README.md in frontkick-0.2.0

@@ -1,10 +1,10 @@
 # frontkick [![Build Status](https://secure.travis-ci.org/sonots/frontkick.png?branch=master)](http://travis-ci.org/sonots/frontkick) [![Dependency Status](https://gemnasium.com/sonots/frontkick.png)](https://gemnasium.com/sonots/frontkick)
 
 testing ruby: 1.9.2, 1.9.3, 2.0.0;
 
-frontkick is a wrapper of Open3#popen3 to execute a command easily.
+Frontkick is a gem to execute a command and obtain status code, stdout, stderr simply, wheres, `system` does not provide it. 
 
 ## USAGE
 
     gem install frontkick
 
@@ -22,9 +22,15 @@
     result = Frontkick::Command.exec(["echo", "*"]) #=> echo the asterisk character
 
 ### Timeout Option
 
     Frontkick::Command.exec("sleep 2 && ls /hoge", :timeout => 1)
+
+### Exclusive Option
+
+Prohibit another process to run a command concurrently
+
+    Frontkick::Command.exec("sleep 2 && ls /hoge", :exclusive => "/tmp/frontkick.lock") # raises Fontkick::Locked if locked
 
 ## Contributing
 
 1. Fork it
 2. Create your feature branch (`git checkout -b my-new-feature`)