Might want to fix the Heartbeat icon link by the way, it currently links to https://heartbeat.appbase.io/heartbeat.appbase.io
As I get it, it's basically a way to keep request rates low.
Rather than every client polling your server every minute (which can be quite heavy), only one (Heartbeat) does, and the rest just subscribe to Heartbeat streams.
Totally makes sense if you haven't planned a pubsub-based API but notice that your RESTful one is close to being hammered into a pulp - so you need something to give to your clients, fast. But I don't think it make much sense as a long-term solution.
In fact, we would like to enable:
1. A lambda function support to transform APIs (diffing to only append new data, adding meta data, removing unnecessary fields) before they get streamed.
2. Polling frequencies of up to 1s.
3. Custom domains for the resulting streaming endpoints.