Isimsoftware helpdesk supports integration with multiple third-party apps and services.
Hipchat - send a notification to Hipchat when a new ticket is created
Slack - send a message to a Slack channel when a new ticket is created
Bitbucket - create Bitbucket issues without leaving a ticket
Jira - create Jira task from a ticket
Github - create Github issues from a ticket
Dropbox - attach files to tickets directly from your Dropbox
Zapier - Zapier support lets you integrate Helpdesk with hundreds of third-party apps
Custom user lookup - the helpdesk app can query some third-party data-source in real time, to get more information about a user (for example, connect to your orders database and show which products has the user purchased, etc)