App Icon Template - Royalty free app icon creator for iOS, OS X and Android
DVDVideoSoft Image Convert and Resize - Free Image Convert and Resize is a compact yet powerful program for batch mode image processing.
Radix Icons - A crisp set of 15×15 icons. Open source.
ImBatch - ImBatch is a batch image processor with a nice graphical user interface.
Drawcon - Draw your own app icons
Caesium Image Compressor - Compress your pictures up to 90% without visible quality loss.