A developer by the name of Jishnu Sir over on XDA created a flashable .zip file in hopes to improve the quality of the Nexus 5 camera. It’s a whole new camera app that replaces the stock one, which will require you to unlock your bootloader and have some sort of custom recovery (i.e. ClockworkMod or TWRP). Here’s a full list of what the new camera app do/improve upon:

1) Sound Recording now in Stereo with the secondary Mic.
2) Faster Focusing for the camera.
3) Front Camera also records 720P Videos@ 20 Mb/s.
4) Front camera Audio Bitrate@ 192000 Kb/s.
5) AntiBanding default set to 50Hz
6) Focus Range Adjusted.
7) Enhanced Smooth Zoom.
8) Turned Edge Enhancement ON.

For more info head over to XDA Devs.