Google+ is now rolling out many of the image adjustment tricks included in its Auto Awesome feature as manual tools — if you use the right browser.
Auto Awesome did an admirable — if unreliable — job of applying image adjustments to photographs uploaded to Google+, but clearly the idea here that a human touch may help somewhat more. So, there are now sliders for brightness, contrast, and saturation, plus highlight and midtone contrast controls. There are also local adjustment tools — which are really handy — and a range of different filters to play around with.
The features have been ported to work in the iOS and Android Google+ apps, but if you're at a desktop you'll need Chrome. It's also worth noting that the feature is rolling out slowly — so don't be alarmed if you don't see it just yet. [Google]