I know a lot of folks (my wife included) who go into this thinking that they just need that next, better camera.
That umpteen Megapixel camera is 5 more than my present one, it'll do such a better job.
I just want to point out that megapixels don't mean much once you pass about 6 MP. Unless you're trying to enlarge past 8x10 that is.
Wife's iphone 7:
My iphone 5:
Both of which are higher megapixel cameras than my Pentax K10:
None of those are BAD shots, mind. But the iphones are both noisy and a little washed out. The reason boils down to camera settings.
Now, I don't know if there's an app that'll let you go manual mode on your iphone or not, but for cameras that do have that option, here's what you need to watch for.
Most cameras and books these days, and all automagic settings will tell you to do 2 things in low light situations:
Open the aperture (aka F stop), and increase the ISO settings. The aperture effects the depth of field of the photo. High iso increases the image noise and washes out the colors.
Thus, shooting in manual, you can get a tripod and eliminate the above problems. In fact, I also use a remote shutter release when I'm shooting to avoid minor bumps from my finger pressing the shutter as well.
This is shot with a Canon Powershot S95. This is a 10 megapixel point and shoot my wife bought, and was a fantastic point and shoot that had some manual capability. Unfortunately it eventually broke...Anyhow, NOT a bad shot here. I don't know if my wife or the camera chose the settings, but F2.2 (aperture, this is fairly open, low = open) and ISO 640. It's not TERRIBLE with the noise, and the colors are good.
However, when I approached this same scene with my then 2006, 6 MP Pentax K100, I knew I wanted to show the depth of field. Thus I ran with an F22, and iso 200. It took me a few trial shots as the exposure had to be soooo long I was manually counting it out as I held the shutter open on the 'bulb' settings. (7 second exposure, my newer camera would have been able to do that without me relying on the bulb setting)
Noise and color are fairly comparable, but the sharpness and detail boil right down to the F stop setting here, not the 'better camera'.