Extensions and add-ons don't display in Photoshop CC 2014.
Update Extension Manager
To display extensions and add-ons in Photoshop CC update Extensions Manager to version 7.2 or later. You can update Extensions Manager via the Apps tab in the Creative Cloud desktop application.
Wait for Extensions Manager or add-ins to populate
When you open Extensions Manager or choose Browse Add-ons there is a short expected delay before the extensions or add-ons display.
Only some extensions and add-ons are available to Photoshop CC
Photoshop CC can only use extensions and add-ons that have been written with HTML5. Previous versions of Photoshop used extensions that were written with Flash, but these extensions are no longer supported in Photoshop CC. Until extensions and add-ons are rewritten in HTML5, they aren't available to Photoshop CC.
If you can download and use Kuler, the add-on functionality is working.
If you have any difficulty installing Kuler, follow these steps: