This panel will help you to even space between selected layers & folders.

What makes this a better option that Photoshop's built in spacing distribution tools?

The distinction is the space between the objects being equal, not just equally spacing the centers of the objects. This is only useful if the objects you are distributing have different widths.

Requirements

Adobe Photoshop CC or CC 2014 or CC 2015
Mac (OS X) or PC (Windows)
How to install for Photoshop CC 2015

Anastasiy's Extension Manager - http://install.anastasiy.com/
ZXP Installer - http://zxpinstaller.com/
Adobe Extension Manager is not support CC 2015.

How to install for Photoshop CC or CC 2014

Adobe Extension Manager CC - https://www.adobe.com/products/extension-manager.html
Anastasiy's Extension Manager - http://install.anastasiy.com/
ZXP Installer - http://zxpinstaller.com/
If you have Adobe Extension Manager installed, you can simply download UberStock from the link supplied after your purchase. Double-click the UberStock-1.0.0.zxp file and Adobe Extension Manager should launch allowing you to install the extension. Once installed, you can find UberStock at Window Extensions UberStock.

If Adobe Extension Manager doesn't launch when you double-click the downloaded file, that likely means you don't have it installed. If you're using Adobe CC (Creative Cloud), open the Creative Cloud helper app, navigate to the "Apps" area, and scroll down to "FIND NEW APPS." From there you can install Extension Manager CC. Once installed, double-click the UberStock-1.0.0.zxp file you downloaded previously to install it.