Now heyzap work on webview and vebview+ (Cocoon, IntelXDK or other cordova platform) but plugin dont work on Cocoon Canvas+ engine - this bug Cocoon. You can use plugin add next for your project:
<plugin name="https://github.com/Verstala2016/tng-cordova-multidex.git" spec="https://github.com/Verstala2016/tng-cordova-multidex.git"/>
<plugin name="https://github.com/Verstala2016/cordova-plugin-extras-google-play-services.git" spec="https://github.com/Verstala2016/cordova-plugin-extras-google-play-services.git"/>
<plugin name="https://github.com/Verstala2016/heyzap-cordova-9.15.1.git" spec="https://github.com/Verstala2016/heyzap-cordova-9.15.1.git"/>
<plugin name="https://github.com/Verstala2016/heyzap-cordova-admob.git" spec="https://github.com/Verstala2016/heyzap-cordova-admob.git"/>
<plugin name="https://github.com/Verstala2016/heyzap-cordova-chartboost.git" spec="https://github.com/Verstala2016/heyzap-cordova-chartboost.git"/>
<plugin name="https://github.com/Verstala2016/heyzap-cordova-applovin.git" spec="https://github.com/Verstala2016/heyzap-cordova-applovin.git"/>
<plugin name="https://github.com/Verstala2016/heyzap-cordova-unityads.git" spec="https://github.com/Verstala2016/heyzap-cordova-unityads.git"/>
<plugin name="https://github.com/Verstala2016/heyzap-cordova-vungle.git" spec="https://github.com/Verstala2016/heyzap-cordova-vungle.git"/>