Rolling, pile up or stitch vertically/horizontally all images.
Reduce image size by change it's resolution or quality.
Trim edge from an image or crop a region on image.
Rotate an image (90, 180 or 270 degrees).
Image color picker (RGB, HEX, HSL).
Apply some graphic effects on image, like mirror, mosaic or sharpen.
Graffiti on image, draw curve or straight line, you can undo every stroke.
Add Text on image, unlimited undo each step.
Generate standard paper size (convert mm to px).