XF 1 - Username Change by Siropu XF1 | BlackSpigot: Leaked Spigot Plugins, Free Minecraft Models & Schematics.

Compatible XF 1.x versions
1.4, 1.5
Visible branding
No
Username Change Add-on allows your users to change their username from user control panel.

Features

Ability to change username in custom tables (for Add-ons that uses tables with username column)
Username Change History
Option to use "Incognito Mode" so that username won't appear in the username history on the user profile page (admins can still see)
Optionally you can set to automatically post forum announcements in the forum you want by the user you want every time a user changes the username (both the thread title and the thread content uses phrases so it can be easily customized).
User Group Permissions (Change username, Use incognito mode, View username history, Maximum number of changes, Minimum days between changes)
Options page (Minimum Days Registered Required, Minimum Posts Required, Announcements Forum ID, Announcements User ID)

A user can't use a username that was used before unless that username was used by the same user.

Install Instructions:

Upload the contents of the folder "library" to "library" folder on your server where XenForo is installed.
Go to admin area > Install New Add-on, and paste in the "Install from file on server:" field the following path: library/Siropu/UsernameChange/addon-siropu_username_change.xml
Install the Add-on.

Reviews are appreciated.