Snapseed is not your typical one-dimensional, tap-to-apply photo-editing app. This popular Google-made app is aimed at more discerning photographers, and packs all of the same photo-editing punch that helped make it famous on other platforms.
When you first fire up Snapseed, the app offers a sample photo and a quick tutorial of its myriad features. I highly suggest reading through the tutorial before diving in, since Snapseed employs a unique scheme of controls that isn't exactly intuitive.
The gesture-based controls might be a little scary at first, but once you play around with them, you'll realize how perfectly they lend themselves to Snapseed's tools. To get started, just pick a tool to use, then swipe vertically to pick which specific attribute, like Brightness or Contrast, to work on. From there, you can swipe horizontally to increase or decrease the intensity of the effect.
A few of the tools, like Tilt-Shift and Crop, require extra tapping and pinching, but for the most part, Snapseed lets you enhance your photos using only swipes. Personally, I love the control scheme, as it adds an enjoyable tactile element to the photo editing, and makes it easy to experiment with both subtle and intense effects. The compare button on the top right lets you compare your 'shopped work with the original shot, which is critical since you can easily get lost in Snapseed's sea of adjustment combinations. Once you're done fine-tuning, you must confirm your work to save. And worry not, the app saves the adjusted photo as a copy, so your original shot is preserved in your device's gallery.
Snapseed's menu of adjustment tools is one of the most impressive I've seen in a mobile app. At first glance, it might look like there are only 13 to choose from, but once you dive in, you'll see that with the submenus, intensity scales (1 to 100), and different adjustment combinations the possibilities are almost endless.