Airtel is back with a free browsing promo/trick. And the good thing about this is that you don't need to have any Airtime credit to activate it. 
No need for tweaks, VPN apps or even changing imei's. 
All you need is to dial the simple USSD Code below and 1GB will be given to you, but you won't be able to use your free 1GB immediately, the plan is only works during weekends (Saturday and Sunday).

To Get Airtel Weekend Bundle of 1GB For Free
1. Make sure you don't have any airtime on your phone to avoid deduction of your money.
2. Dial *475# twice to activate 1GB data for free
3. You will receive a pop up message like: This plan is only available on Saturday and Sunday. And when you re-dial the code, you will see another pop up message like: You have already purchased...
4. That means, your weekend bundle has activated for free! Usable only at 12am on Saturdays till Sunday 11:59am.

I have currently activated it on my simcard, and anxiously waiting for the weekend to start surfing. 

click to begin