Moom - Move your mouse over the green zoom button in any window, and Moom's mouse control overlay will appear (as seen in the above animation).
ImBatch - ImBatch is a batch image processor with a nice graphical user interface.
Hammerspoon - This is a tool for powerful automation of OS X.
DVDVideoSoft Image Convert and Resize - Free Image Convert and Resize is a compact yet powerful program for batch mode image processing.
Spectacle App - Move and resize windows with ease.
Ralpha Image Resizer - High-speed image batch conversion tool