I have been looking all over the internets to find a free glow shader for the free version of Unity. It’s not an easy task because there is no post-processing in this version. You can find some shaders in the asset store but they all work with the pro version except for Indie Glow which i didn’t tried because I found an alternative :

On Youtube  Hired GunGames made a video about Faking Bloom in Unity 4 (Free version) in which he explains how to use his Uber Shader to achieve a glow / bloom effect without post-processing.

glow

Here is a direct link to the shader : UberShader V1.0