iOS/Android: Adobe has today released its Photoshop Touch app for smartphones. It has the same basic features as the iPad and Android tablet apps released last year, including layers, fills and selection tools.
Photoshop Touch works surprisingly well on smaller touchscreens. You can edit photos, crop and retouch easily. You can also do standard cloning, brush and effects. Unique to the smartphone version is a new "Scribble Selection" tool that lets you quickly combine images together, including a live view using your phone's camera. If you're a desktop and tablet user, Photoshop Touch also syncs with the Adobe Creative Cloud so your work is synced across devices.
The iPhone version requires an iPhone 4S or fifth-generation iPod Touch or newer.