Drawboard PDF or PDF Touch
Marking up PDFs is like grocery shopping: mind-numbingly boring, but most of us do it. And that's why the Windows Store's dearth of PDF-markup tools is so disappointing.
From the ho-hum lineup of the apps that do exist, two offerings are worth a try: PDF Touch and Drawboard PDF. Neither of these $3 apps is perfect. Each has numerous interface quirks and the occasional bout of poor performance. But they're what you've got, unless you want to stick to traditional desktop software. Drawboard PDF at least offers a brief trial, so I'd recommend trying that one first.