iPhone and iPad apps tagged "low-light photography."
Ready SteadyCam, Shoot! Get Better Low-light Photos With Darkroom Pro
StepCase's SteadyCam Premium (now called Darkroom Pro) is similar to other apps we've reviewed such as Sudobility's Night Camera. What these apps do is to rely on the iPhone's built-in accelerometer to gauge when you're holding the iPhone steady so you can take sharper pictures in low light.
Night Camera Aspires to Let You See Clearly in Dim Light
I think the iPhone's built-in camera is pretty good, as far as cellphone cameras go. The one thing it, and probably every other cellphone camera, has a problem with, is taking pictures in low light.