Staffpad works MUCH better on the video than in Real Life

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It IS pretty cool, but unless you are a pretty meticulous copyist with a real pencil, it's not as easy as it appears on the Promotional materials.
BTW, I have converted all my legally purchased Kindle fakebooks to .PDF on my Surface. The Windows 10 PDF reader is actually very efficient, and can load multiple Eb/Bb versions into memory for easy switching. Some of them even converted working index pages with hyperlinks to the correct tunes.