Hello im working on a project.I will make a Pay-Per-Install Apk. The app should looks like WHAFF, CashKing or FreeMoneyFactory... The app should store the user data into a mysql database... The user launch the app, make the login or register... he enter to the user dashboard when he can find a TextView with the current point value... the user start click a button and open a offerwall (like everbadge, sponsorpay,w3i... etc), when he complete the offer there's a postback to my website where the php add the amount of the completed offer point to the mysql database and i can find the current total point of user in the dashboard. And it should be a button, cashout that send an email to my address with the current value of points reuqested and him email... I have added offerwalls to my app,but i dont know how to using postback can anyone help me?