This used to be the release repository of Unity Ads SDK 1.5. Unity Ads SDK 1.5 is now deprecated in favor of Unity Ads SDK 2.0. Binaries for 1.5 are no longer available and all new integrations should use Unity Ads SDK 2.0.
First stable version of Unity Ads SDK 2.0 was released on 17th August 2016. It is recommended that all developers using Unity Ads SDK 1.x upgrade to Unity Ads 2.0. Old integrations using Unity Ads 1.x will continue to work but Unity Ads SDK 1.x will no longer get upgrades or bug fixes.
Android releases are available at https://github.com/Unity-Technologies/unity-ads-android
Android transition guide from 1.5 to 2.0 is available at https://github.com/Unity-Technologies/unity-ads-android/wiki/sdk_android_transition_guide
iOS releases are available at https://github.com/Unity-Technologies/unity-ads-ios
iOS transition guide from 1.5 to 2.0 is available at https://github.com/Unity-Technologies/unity-ads-ios/wiki/sdk_ios_transition_guide