UPDATE from 2019: I just realized a lot of people land on this page looking for a demo of our helpdesk app. We used to have a demo back in the days when we offered only the server (AKA "on-premise") version of the helpdesk app. But since we now also offer the "hosted" version that runs in the cloud, we removed the demo because you can easily try the "saas" one. All you have to do is sign up for a trial and you'll be redirected to the helpdesk online demo in seconds (literally). The trial account will stay active for 21 days, and if that's not enough - simply ask us to extend it or register another trial account.
We have just launched an online demo of Jitbit's Help-Desk software. Use "admin/admin" to log in as an administrator, or "client/client" to log in as a regular user. Simply sign up here - enter your email and a get a fully functional demo even with some test-data included.
Even if you're looking for an on-premise helpdesk app to install on your own server - we recommend trying the SaaS version first and try out all the features, integrations, may be even invite a couple of support agents to see how it works for a team. The SaaS demo is fully functional (unlike the downloaded trial that has some features disabled).
Also, check out the video walkthrough we just made:
I just realized, that when I'm looking for a web-app or a component for myself, I never even look at the ones that have no online demos. Offering a server-side product as a download only is never a good idea since system administrators will never install something on their production server for evaluation purposes.