Re: Why?
Well, some keyboards just provide a betters user experience than regular keyboards. The traditional qwerty layout has some basic flaws because it was developed for mechanical typewriters. To fit on a smartphone the keys have to be very narrow.
Other keyboards that solve this by adding mobile-optimized layouts. Typewise for example is a very cool project and is currently available as a free beta. It also has no internet connection permission so the user can be sure that no information will ever leave the device. That's a big problem with other keyboards in my view.
Biting the hand that feeds IT
