This app allows you to resize up to 500 images at once to whatever size in pixels you like, quickly and easily.
You can specify the output format using one of the following four resize modes:
1. Fixed width (Proportional height)
2. Fixed height (Proportional width)
3. Maximum pixel (Proportional width or height)
4. Aspect Fill: Scale the image to fill the output size (Some parts will be clipped)
5. Aspect Fit: Scale the image to fit the output size (Some parts will be filled with the defined color)
Batch Resize gives you the option to save the resized images in Camera Roll and additionally in a custom album.
The maximum output size for 32 bit devices is limited to 4000 x 4000 pixels and for 64 bit devices to 8000 x 8000 pixels.