Recurring Tasks plugin allows to schedule and create issues automatically on specified date and time. It supports well known cron format as well as graphical UI scheduler.

Automated Log Work allows to track time seamlessly in JIRA and JIRA Agile. It offers manual and automated mode so users can pick up the one that suits them best.

Default Values plugin allows to automatically inject predefined values into fields on the "Create Issue" screen. It supports both system and custom fields.

Hide Time Tracking plugin allows to hide time tracking information in JIRA UI from users who are not allowed to log work (users without "Work on Issues" permission).

Fast and easy worklog reports for your team.

Text Highlighter plugin allows to easily highlight selected text on a Confluence page or a blog post.
It offers similar features to iBooks and Kindle apps highlight capabilities.