Is there anyway to improve the quality of pictures that a mobile phone takes at night? This isn't N4 specific, and I know the phone will never take DSLR quality photos, but I figure there must be an app that can change things like shutter speed etc automatically in order to produce better low light photos.
Short of a tripod and exposures that exceed many seconds, no camera is going to do well at night. You're wanting more than technology can currently deliver. As far as shutter speed is concerned, the lens used on a cell phone is so tiny that it doesn't have a shutter (the circular blades that open and close on a normal lens), and therefor, cannot be controlled. Keep in mind that at it's best, a cell phone camera is tiny rinky dink device meant to capture a moment that would otherwise be lost. As long as you have enough light (or can get close enough to use the flash), it does a great job of doing just that. There is a camera app called Camera FV-5 (.) that does give you the greatest control over the camera that I have seen. Specifically related to your post, it lets you do timed exposures for night time photography as well as many other things like selective light metering, selective focus, time delayed operation, exposure compensation, ISO adjustments, and many others. I think it runs 3 or 4 bucks, but if you like using your cell phone camera to the best of it's ability, it's worth it.