There are a couple Bluetooth and infrasound options for pressure sensitive pens for iPad/iPhone. Not as good as a Wacom sensor built into the display itself, bu

There are a couple Bluetooth and infrasound options for pressure sensitive pens for iPad/iPhone. Not as good as a Wacom sensor built into the display itself, but they are there to some degree. The issue is the same on Android. Android devices are so cutthroat that an extra 25$ cost to include the pen and screen sensor will sink your product and not including the pen just makes it into an accessory no one has. And even then you won't beat Google's whitebox or Amazon's loss leader hardware pricing. Samsung is really the only successful Android device maker with a built-in pen, and they already pour ridiculous amounts of money into things no one else but Apple can, like marketing, so it isn't surprising. Although an infrasound pen works with any Android, just not as well again.