One of the many features that Google did not brag about while announcing Android 4.4 KitKat is the upgraded inbuilt photo editor. Shutterbugs will jump with glee upon learning that the photo editor has been blessed with new features, some pretty advanced. Make fine adjustments, apply filters to your photos and even make minute, low-level changes to color channels with this app. Also, accidents can be easily rectified with just a few taps as the editor allows you to undo every single edit made on the original (so it is a completely reversible process).
Here's the video that we were talking about, which includes a pretty comprehensive overview of all the new features.