One of MUST plugins for speed optimization

This has been a MUST plugin for my WordPress speed optimization service along with other caching plugins, works perfectly without any troubles.

Currently all the scripts are delayed at the same timing, but It’d be great if I can set delay seconds per scripts in the future updates. ??

Group A: Delay 1 sec (flying pages, and other small scripts)
Group B: Delay 2 sec (good for adsense)
etc.