ResizePixel is a free online image editor where simplicity is essential feature. It is designed to crop, resize, flip, rotate and convert images to various formats. The service is mobile-friendly, fast and easy to use.
Imgur's Video to GIF - Make a GIF from hundreds of video sites
DVDVideoSoft Image Convert and Resize - Free Image Convert and Resize is a compact yet powerful program for batch mode image processing.
GIFMaker for Mac - GIFMaker – Created a GIF from a video or Images is the easiest way to create an animated GIF on your Mac.
Ralpha Image Resizer - High-speed image batch conversion tool
CONV. - Convert YouTube video to MP3, GIF or MP4
ImBatch - ImBatch is a batch image processor with a nice graphical user interface.