Structure Plugin adds to Atlassian JIRA the concept of issue hierarchy and a new, rich user interface for working with it.
With Structure, you can organize issues into multi-level, cross-project hierarchical lists and share them with your team or with the entire organization.
JIRA Client is a desktop application for day-to-day work with JIRA.
You can navigate quickly through multiple search results, triage issues with drag-and-drop, automatically track time spent on an issue and even work when there's no connection to JIRA.
Pocket Desk for iPhone and iPad is a mobile interface to JIRA Service Desk.
It helps your Service Desk agents keep on top of their SLAs when out in the field by notifying of new and updated issues, and warning of impending breaches.
Deskzilla is a desktop client for Mozilla's Bugzilla bug tracking system.
Deskzilla lets you create your personal workspace, use efficient, centralized navigation through bugs and filters, and work offline.