Change Readme file.

README.md

@@ -1,6 +1,6 @@
 # Schroedinger_SOLVER-IgorPRO
 
-Schroedinger_SOLVER is an Igor Pro procedure (written in Igor 6.3) that 
+Schroedinger_SOLVER is an Igor Pro procedure that 
 integrates numerically the Schroedinger equation with the NUMEROV method to obtain 
 the time-independent -or stationary- solutions, for any given 1-D potential.
 
@@ -11,6 +11,10 @@ To run the code in Igor Pro, simply **Open File > Procedure** from the menu **Fi
 *Schroedinger_SOLVER.ipf* and then go to menu **Macros > Schroedinger Solver**. The main panel will appear after 
 compilation.
 
+Igor version 6.3 or later is needed, and it has been tested in MacOS (Snow Leopard) and Windows (XP).
+
+A quick explanation of how it works can be seen in youtube: http://youtu.be/natEp4Oy9sU
+
 The procedure is freeware in the hope that it can be helpful for educational
 purposes, but without any warranty. I would be thankful for any suggestion,
 comment or bug fixing that could improve this code.