An open source screen space reflection for Unity 5 made by Charles Greivelding Thomas - https://twitter.com/Xerxes1138
UnitySSR require Unity 5 and a shader model 3.0 ( dx9 ) graphic card.
Fisrt make sure your project is in linear color space and you are using deferred rendering path.
Then select your main camera and go to "Component/Image Effects/Rendering/Unity 5 Screen Space Reflection" or drag and drop the unitySSR.cs to your main camera inspector.