if you are an Android user you are free to recieve free airtime.
There are some intresting site, which you can get mobile recharge free of cost. Some sites offers Free Mobile Recharge by matching last digits of your mobile no. with their set of numbers, on a daily basis. Others offer free mobile recharge for completing surveys, offers, install app, etc.
you just need to sign up in their website by going to
then create a new account their with your number and click on my offers there you will find uniliver project just click on that and you will be redirected to the google play store