ShareX - ShareX is a free and open source program that lets you capture or record any area of your screen...
Ralpha Image Resizer - High-speed image batch conversion tool
ScreenToGif - This tool allows you to record a selected area of your screen and save as a animated gif.
ImBatch - ImBatch is a batch image processor with a nice graphical user interface.
recordit.co - Make a short video capture of your desktop as a gif.
Caesium Image Compressor - Compress your pictures up to 90% without visible quality loss.