Peer Services are services which are described by a composite service. InMoov, WorkE, Tracking, Arduino are all examples of peer services. It's very basic configuration which describes something useful.
For example most of the time we want a serial connection of some form to an Arduino, so that we may control and get information from it while its running. The Serial service is a "peer" of Arduino. When you start an Arduino service, a Serial service will start auto-magically. Not, all peers are automatically started when the composite service is started.
For example, InMoov2 has many peers, but they are not called to life unless InMoov2 is explicitly told to start them.
Peers can be started in python by using the service key, in this case chatBot :
chatBot = i01.startPeer('chatBot')
Previously it was not trivial to find out what services were contained within a service. Now its easy, just click on the "show peers / hide peers" in the drop down, and it will tell you its key. In this new table, you can see the key, the name the service will be, its type and its current state.