Top Rated for AppCode

Eclipse Code Formatter

By meo
Allows using Eclipse's code formatter directly from IntelliJ.

Lines Sorter

Add Sort Lines action in Edit menu to sort selected lines or whole file if selection is empty.

GoToTabs

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

Rust

Rust language support.

HashiCorp Terraform / HCL language support

This plugin adds support for HashiCorp Configuration Language (HCL) and HashiCorp Interpolation Language (HIL), as well as their combination used in Terraform...

Makefile support

Support for UNIX Makefiles.

Autoscroll Save

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

RegexpTester

Regular Expression Tester for IntelliJ IDEA.

BrowseWordAtCaret

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

Frame Switcher

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