It's free, though it doesn't really do enough for your use. I use zoomNotes on my iPad with an Apple pencil. It converts hand drawn boxes and shapes, and does e

It's free, though it doesn't really do enough for your use. I use zoomNotes on my iPad with an Apple pencil. It converts hand drawn boxes and shapes, and does exports, but as far as I know doesn't convert arrows. It has a "whiteboard" feature which means a huge drawing canvas, which is very nice. The free aspect for the zoomnotes lite version makes this particularly appealing.