App manager is the run-time container used during Apex Designer development. Design changes made in AD generate updated source files which are synced to App Manager, where a build is run. The type of build depends on the scope of the changes synced, but generally the app builds and restarts within a few seconds, allowing the user to see in near real time the changes they just made in the running app. As well as launching the app from App Manager, the user can launch the API explorer, stop and start the app, and view logs.
