PhotoPenguin App - PhotoPenguin is a completely free batch photo editor with support for cropping, resizing, adding watermarks, and converting photos to other formats. It works on the user's device, using the capabilities of modern browsers.

Online Image Editor - Online editor for images and animated gifs with multiple effects and tools

ImBatch - ImBatch is a batch image processor with a nice graphical user interface.

Pixelitor - Pixelitor is a cross-platform raster graphics editor written in Java.

Batch Image Resizer - Resize, crop, shrink, flip, exif-rotate, convert, enhance, process multiple pictures and photos with professional software! 120+ Actions, 30+ Image Formats

RealWorld Photos - RealWorld Photos is an free portable photo editor for Windows.