Go HDR adds HDR tonemapping as well as Linear Lighting support to Indie Unity games. Go HDR simulates the response of a human retina to changes in lighting conditions. It instantly makes your games look much more realistic regardless of lighting setup. 
Features: 
+ Go HDR doesn’t rely on floating-point buffers. 
+ Bloom support.
+ Unlike Unity’s HDR solution, Go HDR supports almost any hardware you can think of. 
+ Unlike traditional (Reinhard) tonemapping approaches, Go HDR preserves the saturation of black colors. 
+ Go Linear package is included for your convenience. 

Demo link 

Current limitations: supports CG/surface shaders as well as built-in VertexLit fixed function shaders; custom fixed function(VertexLit) shaders aren’t supported; gamma-correction looks best on single-pass shaders, single real-time pixel light scenes and non-transparent objects; this version doesn’t support deferred rendering path; Linux isn’t supported; Flash isn't supported; current version doesn’t support mobile devices;

Please note that Go HDR will double the amount of drawcalls. Bloom effect will also increase the drawcalls and is resource-intensive;