Gmail SMS messaging is now available across a lot more countries, including Asian countries such as Pakistan, Afghanistan, India etc. You can now send texts to a lot of networks in many countries, absolutely free!
Just Follow The Procedure To Send sms From Gmail
Now, hover on a contact of yours, and click on the Send SMS button as shown below.
Once you have entered the mobile number, a pop-up will again appear at the bottom right exactly where the previous one did. This is your chat box. You are now ready to go! Type a message in the text field , hit Enter, and sit back and wait for your friend's reply!