Snapseed interface is controlled with swipes, up and down to choose the option and left and right to choose the intensity. It does take a bit of getting used to, but once you have the interface is very nice and easy to use.
Snapseed includes many features of high end photo editing software, auto correct, image tuning and other effects. Snapseed makes editing your photos easy and gives the photographer many options to choose from in how they present their images.
Scrolling up and down lets the user choose from different effects and tools, swiping left to right determines the intensity. This app includes many effects such as tilt shift that are hard to find elsewhere.
The app doesn't overwhelm you with functionality or hide it behind unlabelled icons. It displays about 5 tools at a time beneath the image and allows you to swipe through the complete list of tools horizontally. Most interactions with the software are kept in that bottom row so you can always see the results of your image manipulations.
There are 20 tools for image manipulation. They allow you to change the sharpness, crop the image, apply filters to it, add frames, etc. There are also tools for one tap redeye and blemish removal.