JPEG Resampler is described as 'With JPEG Resampler you are able to change the resolution and size of JPEG images of a directory in one go and move them into another folder' and is an app in the File Management category. There are more than 10 alternatives to JPEG Resampler for a variety of platforms, including Mac, Windows, Linux, Online / Web-based and BSD. The best alternative is ImageOptim. It's not free, so if you're looking for a free alternative, you could try PNGGauntlet or pngquant. Other great apps like JPEG Resampler are Pingo Web Image Optimizer (Free), OptiPNG (Free, Open Source), Optimage (Freemium) and Black Bird Image Optimizer (Freemium).
ImageOptim is excellent for publishing images on the web (easily shrinks images “Saved for Web” in Photoshop). It's useful for making Mac and iPhone/iPad applications smaller (if you configure Xcode to allow better optimization).
Experimental, fast Web PNG/JPG optimizer which offer lossless, visually lossless or lossy compression. it performs image reductions over iterations thanks to recursive multi-processing and multithreading systems.
OptiPNG is a command-line PNG optimizer that recompresses image files to a smaller size, without losing any information. This program also converts external formats (BMP, GIF, PNM and TIFF) to optimized PNG, and performs PNG integrity checks and corrections.
AdvanceCOMP is a collection of recompression utilities for your .ZIP archives, .PNG snapshots, .MNG video clips and .GZ files. It's mainly intended for recompressing your rom, snapshot and clip collection of emulated games.
Vallen JPegger is the international, handy, and full featured image viewer, which shouldn't be missing on any PC. Currently it supports 27 different languages including full Unicode language and file support. It is designed for large image libraries with thousands of files.