Adobe Photoshop Touch is finally released for phones too, and it's awesome. In fact you can almost do everything you can with the desktop version. I am sure that most of the normal photoshop users will be happy with Photoshop Touch. You can use layers, replace background directly from your mobile camera and much, much more.
It's now available for both phones and tablets on Android and iOS.
• Use popular Photoshop features, such as layers, selection tools, adjustments, and filters, to create mind-blowing images.
• Improve your photos using classic Photoshop features to bring out the best in your photography. Apply precise tone and color adjustments to your entire composition, a particular layer, or a select area.
• Create something other-worldly using painting effects, filter brushes, and so much more. With Photoshop Touch, the creative possibilities are endless.
• Make your images pop with graphical text. Apply strokes, add drop shadows and fades, and more.
• Take advantage of your device’s camera to fill an area on a layer with the unique Camera Fill feature.
• Quickly combine images together. Select part of an image to extract just by scribbling with the Scribble Selection tool. With the Refine Edge feature, use your fingertip to easily capture hard-to-select image elements, like hair.
• Start a project on your phone and finish it on your tablet* or back in Photoshop** at your desk using a free membership to Adobe Creative Cloud™.*** Your projects are automatically synced between your devices.
• Free membership to Creative Cloud provides 2GB of cloud storage.
• Work on high-resolution images while maintaining the highest image quality. Images up to 12 megapixels are supported.
Google Play Store