TPU case is for the back only.
Nobody would be able to use the phone with a front TPU case.
I've read Diztronic, Amzer and the likes are good. Search in amazon or ebay for similar priced ones. DON'T buy cheap silicone ones.
You can check this for TPU case front and back...
Samsung Galaxy S2 i9100 (White) Complete Front & Back Tpu Jelly Rubber Gel Skin Case Cover: Amazon.co.uk: Lighting
thanks for suggestion..
Is google's official back case for N5, is TPU case??