I have uploaded a new widget to the share site:

https://share.servicenow.com/app.do#/detailV2/4775d202db4ad700b960a6e51b961940/overview

This widget can give you a progress bar UI to track the progress of any background jobs that were started using the sys_execution_tracker. Examples include Plugin installation and update set installation where you generally see a popup with a progress bar showing the status of the work. But more importantly, you can create your own Background processes using the sys_execution_tracker table.

A good use case for this is if you have a long running process that needs to be kicked off by the user in the portal. If you try to do this through a regular REST call, it is subject to the transaction quota rules and could be cancelled before your code completes.

With this method, you can offload the work to a tracker and show the progress on the UI as it completes.

Screen shot of a multi-hierarchy job (plugin installation):

Screen shot in a modal window:

There is documentation attached to the share site as well, and a working sample in the update set, so you can see how it works.