Hi Mahlon,
Sorry for the delay, I had to ask around for more information on this one.
We do plan on releasing a documents app for M:N however, it has not made it into our roadmap yet. We have some other apps such as Field Services that have a greater demand, which we are going to release first. As always, I cannot provide an ETA for when new apps or features will be available.
If you have an immediate need for a documents app, the functionality exists for you to build one yourself. At this time, the only thing that would be missing is SmartVault integration. This is something that we will be working on releasing along with our documents app.
I hope this helps.
-Audisho