A free app for Android, by Anforapps.

When you have a great picture, but it is a little too dark or has a lot of noise, you can enhance it with “Camera Super Pixel”. It will improve the resolution, sharpen the image, and reduce the noise. It is also optimized for static scenes, so you can get better results in other situations. A higher resolution image is produced by the Camera Super Pixel by first taking a number of photos and then applying a custom super-resolution algorithm. In this app, you can as well use the front camera of your device.  You can find the list of phones that are compatible with this app here: Samsung, Nexus, OnePlus, Sony, LG, and Mediatek.