If you love to edit and play with your photos, Pixlr Mobile is a powerful app that has almost any tool you could want.
VSCO Camera provides great tools and filters for traditional photography corrections and adjustments, but it lacks fun special effects.
Adobe's Photoshop Express Mobile is a simple photo app that delivers on image quality and ease of use, but it doesn't offer as many tools and controls as other apps.
PaintShop Pro X7 is good for families with varying skill levels; though less versatile and powerful as Photoshop Elements, it’s far cheaper.
Elements 13 delivers easy guided photo-editing, fun projects, a creative learning experience and accessible power for more-experienced users.
Picasa is a convenient, effective editing program for users who want to quickly prep their pictures for sharing — especially on Google+.
Photoshop CC enables the greatest level of creativity, with top-quality image editing and compositing, plus enhanced collaboration tools.