Disclaimer: I have no idea how it will interact with other map addons. This is a pet project of mine that I come back to from time to time and work on it. I'm uploading it for mine and friends convenience. I figured others might want something like this as well so figured why not.

This addon gives you a toolbox on the left side of your map with various paintlike tools for drawing on the map. Clicking any tool will place you into edit mode which is indicated by the tinted display of the map. Right clicking the map or closing it will take you out of editing mode.

Tools

Paintbrush - draw lines on the map. Right click will give you color options.
Icon stamp - clicking will place icons on the map. These will be visible on the minimap as well. Right click will allow you to choose different icons.
Eraser - erase anything on the current map. Right click will allow you to clear the current canvas, clear a specific canvas or clear everything. This includes all points shared or otherwise. There is no undo.
Ping Map - clicking will place an animated ping onto the map.
Icon Text - clicking an icon will bring up an edit box. This text will be attached to the icon as a tooltip.
Title Text - clicking on the map will bring up an edit box. This text will be displayed as a large font title.
Comm Options - Toggle for receiving from leaders only. Also contains a list of players you have received data from. Unchecking will block data from them.
Share and Receive checkboxes - when checked will share or receive data with the party or raid. Share is turned off by default when game is loaded.

Canvas