Uploader
The new upload dialog offers the option to edit and preview files before the upload.

Optimize Files On Upload
File blueprints can now set resize and crop settings, which will be applied directly after the upload. This is great to avoid huge original files in the content folder.
title: Image
create:
width: 500
height: 500
crop: true
This feature also adds a new $file->manipulate(array $options)
method. It takes the usual resizing and crop options of Kirby's image processing API and replaces the original file with the resized version.