CastarSDK is described as 'We are a team focused on providing developers with innovative app monetization solutions. By integrating our SDK, your app can realize a steady passive income without compromising the user experience. Earn up to $500 USD per 1,000 effective exposures, with earnings based on the' and is an app in the development category. There are more than 25 alternatives to CastarSDK for a variety of platforms, including Android, Web-based, iPhone, Android Tablet and Windows apps. The best CastarSDK alternative is Google Opinion Rewards, which is free. Other great apps like CastarSDK are Honeygain, Earnweb, NiceHash and GrabPoints.