Thinking about this some more: it would be very straightforward to implement a leveldown API on top of fly.cache. That, paired with something like PouchDB, would give you an edge database. You could have one big centralized CouchDB server with a bunch of PouchDB clients at the edges.
Hmmm...
Right now it's _best_ suited for building proxy-like applications. Aggregating APIs, speeding up existing apps without touching them, user aware caching, etc.
But we're getting constant pressure to expand the scope of what they do, too, which is pretty exciting.