FastStone Photo Resizer as the name suggests is a tool for resizing and converting multiple photos at once.
This application supports all major image formats such as JPEG, bitmap, GIF, TIFF and PNG among others.
Apart from that you can also batch rotate, crop, rename and do a few other things to your photos with this app.
Processing time is quite fast and this app is useful for anyone who would like to re-size many photos at once so that they will be much smaller in size for storage on your hard drive or online. FastStone Photo Resizer is a proprietary Windows software and available for download at the developer's website here.