You can find a number of very useful conditions, validators, and post functions with this add-on. For example, the Update Issue Field post function that ships with Jira allows you to update any issue fields such as priority and assignee when a workflow transition completes. The Suite Utilities for Jira add-on complements this by providing a very similar Update Any Issue Field post function, which handles custom fields. There are many other useful components such as the Copy Value From Other Field post function, which will allow you to implement some amazing logic with your workflow. It is a must-have add-on for any Jira. You can find out more at https://marketplace.atlassian.com/apps/5048/jsu-suite-utilities-for-jira.