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.
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.
Ralpha Image Resizer - High-speed image batch conversion tool
MakeAppIcon - MakeAppIcon resizes and optimizes your icon designs into all formats needed for iOS and Android mobile app!
ImBatch - ImBatch is a batch image processor with a nice graphical user interface.
Ayecon - Ayecon is an app that allows you to easily make icons according to the required dimensions.