The Herzum Quick Linker Add-on is a powerful JIRA add-on that gives you the ability to quickly create & link issues together, but also creates a configurable mechanism of synchronization between specific fields.  Quick Linker is designed to allow you to create an issue from within an existing issue and automatically link the 2 issues together. Quick Linker has the ability to create issues within the same JIRA instance and project or across different JIRA instances and projects – defined by you within Quick Linker's robust  Administration Panels.

The Quick Linker add-on provides the following key features:

• A user friendly configuration panel that allows you to define the mapping you needs between projects and issue types
• Create and link issues automatically
  • Links across different JIRA instances
  • Links in the same JIRA instance
  • Links through different projects
  • Links in the same project
  • Subtask links
• Keep JIRA issues fields in sync automatically
• Rank the linked issues 
• Search issues via JQL function based on quick links filters

Follow the links below to learn more about the mentioned features: