I'm sorry I may be stupid but I still don't understand how the keyboard works after having seen that second video. Seriously they should make a video where we can see what happens on the keyboard and on the screen at the same time.

Why every time the finger starts to slides the only letters left on the keyboard are "EABCD"? How do I type an 'n' for instance? I see that they do a round-trip to enter numbers, but how am I supposed to enter '6'?

These may be the worst demo videos I've ever seen.

I remember another alternative-paradigm keyboard, 8pen, which had pretty good and instructive videos. They should learn from that.