DrawAnywhere lets you sketch, annotate, and highlight directly on top of any screen. Great for following along video courses, recording tutorials or hosting presentations.

Highlights:
<ul><li>Stroke eraser toggleable via stylus buttons</li>
    <li>Touch passthrough to the app below</li>
    <li>50-step undo/redo operations</li>
    <li>Minimal storage usage</li></ul>
Tips:
<ul><li>Long press and drag to move the toolbar around.</li>
    <li>After 3 seconds of inactivity, the toolbar becomes more transparent.</li>
    <li>Turn on <tt>Clear on hiding canvas</tt> to let the app clear the canvas when you hide it.<br>
Note: Touch passthrough will be turned off automatically as well.</li>
    <li>Turn off <tt>Canvas visible on start</tt> to hide the canvas on startup by default.</li></ul>
Source is available on GitHub: <a href="https://github.com/shezik/DrawAnywhere">https://github.com/shezik/DrawAnywhere</a>