For OpenStreetMap(OSM) mapping, drawing your memo on paper printed the OSM map is good solution. You can describe on the paper anything e.g. Line, words, arrow, symbol and illustration. "OSM sketch" realize such paper mapping on smartphone. You can draw on OSM map anything you want to memo anywhere, anytime without printing beforehand. Operation is easy and optimized for small screen. Multi touch operation ,scroll and zoom, can be executed also during "drawing mode" so you can pull new canvas o