Just a quick heads-up that onOne software are currently giving away their Perfect Effects software for free for a limited time. The software normally retails for $99.95.
Perfect Effects is designed to allow you to apply a range of enhancements to your images. Each enhancement has a range of options allowing you to tweak the results to your liking. There are plenty of presets included, and you can also create your own or download more from the web.
The software supports layers, including layer opacity and blend modes. It is stand-alone software, so it doesn't require other image editing software such as Photoshop. While it's not a replacement for a full image editing program (in my opinion), there is certainly a lot you can do just in Perfect Effects.
The main negative about the software is that it has high minimum system requirements - it requires 8GB of RAM and a 64 bit operating system. If your computer can handle it, then I'd recommend getting your free copy of Perfect Effects while you can.
If you're wondering why they would give their software away for free - onOne are probably hoping that you'll like the software so much you'll decide to upgrade to their full Perfect Photo Suite.
Of course, as part of the purchase process you have to supply your email address, so they can send you emails. These emails often include links to new tutorial videos they've posted, but you can always unsubscribe if you don't want them emailing you.