Picmonkey : Best Photo Filter App

PhotoLine sports a pretty heavy set of features: 16-bits-per-channel processing, ICC profile color management, IPTC and EXIF data handling, extensive image processing features, filters, correction tools, batch conversion support, and much more.

PhotoLine is positioned as a less expensive alternative to Photoshop, but its clearly aimed at the same users - people who already have a lot of image editing and manipulation experience. Its user interface is a bit wonky, although its feature list is impressive. Dont expect to dive into this app and know what youre doing without having a good handle on the fundamentals of image editing tools, however.

A demo version is available for download from the PhotoLine web site, so feel free to check it out and judge for yourself.