Photoshop has become so pervasive in the last few years that, like Google, it's become a verb: 'to Photoshop' has became shorthand in common parlance for editing an image. Which might give the impression that Adobe's got the market sewn up - but that's not actually the case.
Pixlr claims to be "the most popular online photo editor in the world", which may have something to do with the fact that it's free.
But it also boasts more than 600 effects, overlays, and borders and lets you do all the main things you'd expect from a photo editor, from cropping and re-sizing to removing red-eye and whitening teeth.
And if you're used to using Photoshop, then you'll find Pixlr's user interface easy to pick up quickly, as it's very similar. This free app is available in both iOS and Android varieties.
Of all the tools featured in this list, PhotoPlus X6 is perhaps the most direct competitor to Photoshop in terms of trying to replicate the different tools in Adobe's software for the PC at a lower price.
It's definitely a case of getting what you pay for. To be frank, the tool can be tricky for beginners to use, and lacks the slickness and reliability of its big-bucks competitor.
But in the right hands it's possible to create quality work with PhotoPlus X6, and at under $90 it represents a huge saving on buying Photoshop CS6 or subscribing to Photoshop CC.