You must register on the app! TapSmash is a user friendly app by which you can earn FREE REWARDS!! To earn free rewards u just have to open the app where you will see the offer wall containing lots of offers which can give you a huge amount of recharge money all you have to do is just download these apps as per given conditions after which your paypal account will be automatically recharged.
You MUST register to get credit.
Make sure you open the app after installing.
If you uninstall mCent, you will NOT get credit