app similar to MS Paint to edit documents
basically I am editind this picture from the web its a scale of musical fifths...I want to edit it.. just add a few little things and erase a few things... Preview is working nice, just to add a few lines and stuff, but... I dont see an eraser tool.. :/ is there a better app for this?
MacBook Pro with Retina display, OS X Mountain Lion (10.8.2)