The SDK contains source code for iOS platform.
Please note that SDK is ARC (Automatic Reference Counting) based now. If you have non-ARC project you either should include SDK as a subproject or specify -fobjc-arc compiler flag for the SDK source code.
The guide for SDK integration is available on Pushwoosh website:
http://www.pushwoosh.com/programming-push-notification/ios/native-ios-sdk-integration/
The sample project is available here:
https://github.com/Pushwoosh/pushwoosh-native-samples/tree/master/iPhone
Documentation: https://github.com/Pushwoosh/pushwoosh-ios-sdk/tree/master/Documentation
Pushwoosh team http://www.pushwoosh.com