Exciting news! With the popularity of this new module we backported it to 4.1.x, 4.2.x and 4.3.x! Now it's available for 4.1.x though 4.5.x!
To celebrate, we've extended the 15% off sale until next Tuesday April 16!
http://www.bcsengineering.com/store/x-cart-speed-booster.html?MMCF_xfBooster
Carrie