Is there an IOS app that mimics "while you were out phone message pads"
Yes. Notes app does this perfectly on iOS 11. 

Take a picture of the paper, crop and color correct if you please. You can also or store in iCloud Drive, photos or store on the iPad as a file, but I kind of like the notes app.

Then annotate the image with text typing, finger drawing in pen, pencil, marker or use a stylus or Apple Pencil on iPad. 

Then send the file using messages or any other app.