From J2Play

The J2Play store provides a way for customers to cash in the credits they've earned for rewards as well as a way to sell or unlock custom game content.

J2Play Rewards Store

The default J2Play rewards store provides a variety of ringtones and wallpapers for mobile phones that customers can trade in their credits for. It's populated with continually changing content by J2Play.

J2Play Custom Game Store

If you have assets that you want to provide to your users as rewards for playing, you can provide them to J2Play and they will in turn make them available only when users are playing your games. Examples of such items could be mobile ringtones and wallpapers, or desktop wallpapers or promotional items.

J2Play PC Downloadable Purchase Store

If you want to allow users to unlock full versions of your PC Game through a purchase, you can do it here as well. In order to distribute an unlockable game, follow the DRM instructions in the C++ documentation. This facility is perfect for providing a Trial to Buy PC Game in which a player can play a limited version of the game until the full version is unlocked in the store.

Instructions for adding DRM to your C++ game can be found here: C++ Documentation