"Offline viewing allows you to cache up to 30 course modules on your mobile device. Simply choose the modules you want to watch offline and our app will cache them on your device. It's super simple. Each module will automatically be deleted after 30 days (or when you no longer have a Plus subscription) and you can always choose to delete them manually to make room for more."
They reach into your device to pull stuff off! Ugh.
No single purchases either, because they don't actually sell anything.
Here's hoping that the OSS, no-DRM, buy-to-own ideas from PeepCode take hold at PluralSight.