PicShop is not bad. Has some filters, basic resize and red eye remover. Also has colour adjustments and croping. I find that it is pretty good over all. There is a free version as well so you can give it a go at no expense.
The apps suggested are all reasonable and will get the job done but if you want something like Photoshop for a tablet, that app doesn't exist for the Playbook. Sadly a version of Photoshop Touch is also highly unlikely since the Playbook's screen size and resolution do not meet Adobe's minimum standards.
I use a work-around, since I was into digital photography before I got my PB. I have PhotoShop Elements on my laptop and do my editing by copying the file to the LT, then back to the PB. Takes a little longer, but PSE can handle some serious correction.
