Ruin Explorer
Legend
Great minds think alike lol. I used a PDF tool but otherwise very similar. I still have reams and reams of PDF'd monsters and reskins and so on on my Google drive.DDI was very helpful. I did what you are talking about, just went through the monster stat blocks, found ones that did what I wanted, quickly reskinned them in the monster tool, and printed out the stat blocks to files, pulled them all into GIMP, filled pages with them, and then saved them to my wiki and printed out a copy to use at the table. lol.
EDIT - Oh wow actually lie I see I did EXACTLY what you did at times, I've got image files where I must have chopped stuff in so I could cram more on a page for printing out.
But yeah point is that was easy DMing days, and 5E has never since got back there, sadly.