Since JFU 2.13 there is also an editor extension of JFU available. It does fully replace the existing "Image" button below the artice editor and gives you the full power of JFU:

• Tested with php 7 and Joomla 3.7.5
• New: Preselection of uploaded files and created thumbnails
• Full integration of JFU in the editor. You can upload multiple files instead of only one file like in the Joomla implementation
• You can use groups and profiles - this makes it possible to define exactly where each user can upload files.
• Use the server side to select images you want to insert.
• Add a link target by simply selecting it in the server side view.
• Create thumbnails of existing images and include them.
• Define the size of the image you want to include
• Support for Lightbox, Lytebox and Highslide
• A nice ruler - because I don't know how much 300px are :).
• Caption support! You can create automatically a div or span that in includes your image + your text. Please see the description below!
• JFUploader Editor extension can be configured.
• Links can be inserted
• Thumbnails of pdf's can be created.
• Google doc viewer can be used directly.
• Html and css was optimized to work with different templates (some templates destroyed the divs)