Adobe Photoshop Express
Adobe Photoshop Express just showed up in the Windows Store. It looks pretty simple, but this is the big name type of stuff that's really good to see showing up.
It's free, but the "Noise Reduction Pack" and the "Premium Looks Pack" (a set of filters) are $4.99 each. You can preview how the packs will affect the image, but you can't actually save the changes unless you buy them.
It looks to me like Fhotoroom and Fotor are still more powerful apps, so hopefully Adobe will continue to improve this. But again, even just having Adobe working on the platform is a good sign.