Forget screenshots, it's just a hex converter.

It loads a file and shows the hex code in a textbox
that you can copy out of to paste into something else,
or, if you paste hexcode in, it saves that to a file.

The code (hexer.r):
rebol [title: "Hex Converter"]

view layout [
  origin 2x2 space 2x2 across
  a: area 500x480 font-name font-fixed return
  btn "Load File" [
    s: mold read/binary to-file request-file/only
    a/text: copy/part at s 4 ((length? s) - 4)
    show a
  ]
  btn "Save File" [
    b: load rejoin["#{" a/text "}"] 
    write/binary request-file/save/only b
  ]
  tt "Load & save files; cut & paste hexcode"
]