Can a part expose an app to parent snap

So I’m building a ‘part’ that is designed to be included from a snap.

The part has a couple of apps that need to be exposed via the final snap.

I can’t find any documentation that suggests how this is done.

Can the part just declare an app and it will automatically be visible from the snap or does the snap need to re-declare the app?

Here is my part:

And here is the sample snap that wants to use it.
At this point I’ve tried re-exporting the apps, but this feels unnecessary.
(I’m currently having trouble getting this snap to build due to the part not being built but that issues is the focus of another post Access remote/local parts).

name: orion-monitor # you probably want to 'snapcraft register <name>'
version: '0.1' # just for humans, typically '1.2+git' or '1.3.2'
summary: monitoring of orion vms.
description: |
  OrionMonitor is a webapp designed to monitor Orion Vms and     stop/start them
  when they are not required.

grade: devel # must be 'stable' to release into candidate/stable channels
confinement: devmode # use 'strict' once you have the right plugs and slots

apps:
  tomcat:
    command: tomcat-launch
    daemon: simple
    plugs: [network, network-bind]

  # used to ran the certbot renewal process.
  cron:
    command: cron
    daemon: simple
    plugs: [network, network-bind]

  # You must run getcert after the install to create the certificate.
  getcert:
    command: getcert
    plugs: [network, network-bind]

parts:
  # build the web app
  orion-monitor-webapp:
    plugin: maven
    source: git@bitbucket.org:sbsutton/orionmonitor.git
    maven-options:
      [-DskipTests=true]
    organize:
      war/orionmonitor-1.0-SNAPSHOT.war : webapps/orionmonitor.war
    after: [tomcat-with-ssl]

  tomcat-with-ssl:
    plugin: dump
    source: ../../../tomcat-with-ssl
    #source: https://github.com/bsutton/tomcat-with-ssl-snap
    #source-type: git