If you Google on seam carving, image retargeting, inpainting, &/or liquid resizing [to name a few], you'll find info on software methods to analyze & alter an image, e.g. http://en.wikipedia.org/wiki/Seam_carving . From a quick look that doesn't seem to be what Photo Retoucher uses or does at all, at least compared to apps like Inpaint, so that sort of comparison doesn't really work. Seam carving etc. is not ideal for everything, so not having it is not necessarily bad. Here's what it does so you can decide for yourself whether you might find any of Photo Retoucher's features useful...
Import or open an image file in Photo Retoucher & you can adjust basic contrast, brightness, saturation, along with rotate & crop to selection. The Concealer brush is a very basic air brush tool -- it's called Concealer I imagine because you can set it to any color in the image by right-clicking with the cursor over the part you want to sample [in most image editors you'd use the Eye Dropper tool to set the foreground &/or fill color, & then use whatever brush you desire]. The Undo Brush is likewise a very basic air brush allowing you to paint with the original image. The Scratch Remover is standard fare, but again pretty basic in that you can set the size of same-color blocks you want to get rid of, but not strength or tolerance -- OTOH it selects what it detects as scratches 1st, actually fixing anything is a 2nd step, so you have the opportunity to de-select whatever before clicking the Remove button. The Spot and Noise Remover is again very basic compared to the usual, & accompanied by an equally basic Smudge Brush. Sketch is simply an overall effect you apply to the entire image -- you have 15 presets but rather than being live, the preview just shows you what will happen using a built-in image. The Remove tool seems to clone the area surrounding a selection in all directions -- the only control you have over what's cloned is the Fill texture size in the Tools menu -> Options dialog. The selection tools are again pretty basic -- there's a Free-Form Select but it only works by click-dragging rather than the sort of connect the dot process that's both more common & more usable. The rectangle select does not seem to include an option to do squares [usually a hot-key], nor is there an option for circles/ellipses, while the Selection Marker simply lets you set the brush radius to paint on your mask. There are no feathering or transparency settings available for any of the mask tools, nor can you add/subtract from masks or save or remove them.
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Personal opinion... Doesn't have anything that I would say approaches unique, so with a few decent photo editors already I won't hang onto this one the way I do Inpaint. From the opposite perspective, for someone who doesn't do a fair amount of image work, there's something to be said for simple -- it takes time & effort just to browse through the options in a more complete app, & then you have to choose something & usually make some settings, so I'm sure there are folks who'd be just as glad not having that bother. Photo Retoucher doesn't do a lot compared to those, more complete editors, so I was able to easily enough go right down the menu bar ticking off the tools & what each does.