I recently wrote a useful application that does not have its own UI. Your users probably already have enough primary applications to work with so adding another will make their life more complex.
Instead the application writes the data it finds into the application they are already using. I have used this technique now with Contentful, Teams, and now Zendesk.
The trick is to combine webhooks from the application with some form of comment API to write what you need where the users are already working.
In this case I notice that a ticket has been submitted with some metadata and a well known pdf structure. The app reads the pdf, parses it and checks the details against what we have stored on our systems. It also writes both back to the ticket with a list of differences. This means that the user does not need to open the attachments (or our system) to start work.
Developer Rants 