How to tell if a collection or an article has downloaded to the device?

I'm wondering if there is any way to force an entire collection to download to the device, or at least to tell which article(s) in the collection have been downloaded? This is particularly important in sales enablement applications. We want to be sure that a sales person has all the content they need downloaded to the device before a customer visit. I don't see an indicator anywhere for this? How does this work, or is this functionality coming soon?