Welle Smart Interface Controller

Watch out. Read the comments on Kickstarter before buying. There are only smartphone apps available yet, and those seem to be not really functional. This thing seems to be dead in the water.

As one of the backers on the original kickstarter - this is a pretty cool device, but don't expect it to just work out of the box. The surface you put it on has a huge effect on how well it works, and I've never really gotten it to be super accurate. Admittedly, I also haven't put all that much time into getting it to work, so I'm sure it can be done - just expect to have to do some finagling.