Shooting in low light is a challenge. Even with the correct exposure, low-light photos (or photos with shadows or other dark areas) can turn out grainy, with digital noise distorting if not ruining your shots. Noise is particularly prevalent with low-light photos taken with smartphone cameras, where you don't have the option as you do on a dSRL to lower the ISO.
Many photo-editing apps feature a way to reduce noise, but Noiseless by MacPhun makes it a quick and painless process with impressive results. It can be as simple as loading a photo and selecting one of the presets along the right side.
In the center, Noiseless shows you a preview of your photo. You can view before and after images side by side to see the effects of your chosen preset, or you can view a single image with a vertical line that you can slide across the photo to see the effects (left of the line is the original image, right of the line is the edited version). Each preset has a slider to adjust the intensity of its effect, and you can also switch from Presets to Adjust in the upper-right corner for finer edits.
Noiseless costs $17.99 (£13.49, AU$22.99) in the Mac App Store, and MacPhun sells a Pro version for $49.99 on its site, which adds two more presets, support for RAW images, and the ability be installed as a plug-in for Aperture, Lightroom and Photoshop. You can also download a free demo of Noiseless Pro from Macphun.