1GB free from Airtel no Tweaking at all rocking well

All you need are;
An android and airtel sim
Send keyword S356241060196*** (generate the last three digits with imei analyser) and send to 232.
You will get a reply "Welcome to the smartphone network... Bla..bla.bla"
Then again send "Join" to 141 and voila! You'll be given 1GB for 1month it works truly