Top Rated for AppCode

Multirun

Allows to run multiple run configurations at once: group multiple run configurations and start them in a single click.

GoToTabs

The plugin adds menu actions allowing you to go to a specific tab.

Run Configuration as Action

Register all run configuration as actions.

PlantUML integration

PlantUML diagramming tool integration.

JetForcer | The Smartest Force.com IDE

JetForcer is the smartest Force.com IDE for handy Salesforce development with JetBrains IDEs.

Frame Switcher

Plugin for more convenient switching between projects/frames/windows than is alt-tab or Window menu.

Rainbow Brackets

Rainbow Brackets / Rainbow Parentheses for IntelliJ based IDEs.

Free MyBatis plugin

Free Mybatis plugin.

BrowseWordAtCaret

Allows to easily browse next/previous word at caret and highlight other appearances of selected word.

Autoscroll Save

At last, a handy way to save your Autoscroll to/from Source settings :).