README.md in nakal-0.0.3 vs README.md in nakal-0.0.4

@@ -1,10 +1,11 @@
 # Nakal
 
 Automated visual testing of Android/iOS applications
 
 ## Installation
+You need to install [imagemagick](http://www.imagemagick.org/script/index.php) on your machine
 
 Add this line to your application's Gemfile:
 
     gem 'nakal'
 
@@ -20,21 +21,33 @@
 
 If you are using cucumber, include following Lines in your env.rb
 
 	require "nakal/cucumber"
 	Nakal.platform = :android
-	Nakal.directory= "<your_project_dir>/baseline_images/droid"
-	Nakal.device_name = "samsung_galaxy_s3"
+	
+	for ios, set:
+	
+	Nakal.platform = :ios
 
+
 and then put this line in your automation code, at all places where a new screen loads:
 
-	diff = nakal_execute("current_screen_name")
+	diff_metric = nakal_execute("current_screen_name")
 
-Now, execute your test by passing env variable NAKAL_MODE=build to build the baseline images
+Now, execute your test by passing env variable NAKAL_MODE=build to build the baseline images. All baseline images will be stored in baseline_images folder in current directory
 
 once baseline is built, next execution onwards, start using environment variable NAKAL_MODE=compare to compare against baseline.
 any difference will be put in the same directory with image file named "current_screen_name_diff.png"
 
+## Important
+
+* This works best when your tests are running against mocked data
+* If test data keeps changing for each test, use diff_metric (output of nakal_execute method above) to determine if the change is acceptable.
+
+For setting custom directory, use:  
+
+	Nakal.directory= "<desired_directory>"
+	Nakal.device_name = "nexus7"
 
 For cropping the notification bar OR scroll bar, create a config/nakal.yml file in execution directory
 
 eg: