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The Pencil tool draws lines, and the eraser removes them. The shapes tool allows you to use a paint bucket, rectangle, line and circle tools. Two finger drag and zoom anywhere to navigate large images. There''s a full undo/redo stack, as well as a color picker with history, hsv, rgb, and hex!
As always, email with problems, suggestions, etc. or leave me a comment on the XDA thread: http://forum.xda-developers.com/showthread.php?t=1266603