Front iPhone 5S camera grainy?

Okay so the front of my 5S is really grainy when I take pictures and you can hardly see. I've noticed that inside that the glass covering the lens is shattered. Is there anyway that I can get that fixed with out getting a new iPhone? And my phone is jailbroken so the warranty is voided.

Check with your local Apple repair shop. My grandson worked in one and they fixed all sorts of things.

What you are calling "grainy" is really noise caused when a camera is using a high ISO setting.

The broken lens is a whole different matter. It will cause some other issues which will lower the quality of any images you shoot using that camera.

All you can do is take it into an Apple store and get an estimate for the repair.