Good, not great. But prob best in its category.

Seems theres few batch resizers around, so of those available, this is the best option.

Major Con: theres no labels for dates of photos.
When selecting the pics to resize, it sorts it by date last taken, first. Theres no other way to sort the pic.
So if you happen to take multiple pics on various dates, the sorter just shows the photos with no way of knowing when it was taken.

Another con: size limitations. The max is 2048. So for iPhone 6S+ users, there is a drastic loss of image quality and image size.

One Seven Seven about Reduce - Batch Resize Images and Photos for iPhone & iPad