What will you provide in terms of image editing, that something like pixlr doesn't? I currently use that for image editing, since Gimp is just total rubbish to use, and I need a damn "business case" to get Photoshop.
Well, currently Photo Pea has much better support for PSD than Pixlr (e.g. more layer effects, folders of layers, vector masks ...) Pixlr also uses Adobe Flash, wich is not available on some devices.