Why aren't there any (or are there?) pressure sensitive bluetooth stylus for Android?

So, I found this stylus, which is the bluetooth version of the Adonis Jot, one of the more popular stylus (although I've read that the disc can scratch the screen), and I found a really cool feature. On iPad, if you pair it with bluetooth, it becomes pressure sensitive, like Samsung's S Pen. There are plenty of apps for android that support pressure sensitivity, so why can't this work on Android as well?

It would also be super awesome if it would have palm detection. I'd really like to be able to use it to take handwritten notes on my Nexus 7 in class, because with a regular capacitive stylus, it's too thick to work well on a 7 inch display.