I'm looking for a WordPress image resizer, not one that resizes the image when you upload it, but one that resizes your image as soon as you access it (I'd like to keep the high-res images as high-res).
So if you uploaded a raw 5000x5000px image and it display a 100x100px image on your blog, I want it to resize the image the first time you access it and cache it as a 100x100px image instead of loading the 5000x5000px image every time.
The plugin Hammy seems to do this, but it's very outdated and no longer works.