Not gonna write a long post here, since I already did a rather concise yet lengthy write-up about the script on WPExplorer.
What the script does basically is to resize and/or crop images from WordPress on-demand. It is easy to use, fast, secure and efficient.
One of it’s most important ingredients is the implementation of WordPress built-in functions, meaning it’s completely native. You know what that means – No more 777 folders, manual querying database for attachment id etc. Just feed in the url and you’re golden.
The script is now singing and dancing on Github so go grab it while it’s hot. If you have issues with it please, please, please post it on its Github issue page, and if the script saved your life please give me your sister’s contact no.
P/S: Thanks to AJ for testing the script and for that awesome looking feature image. I hope you live up to 90 and have many kids.