[mcb3k]

If you don't mind getting your hands dirty, you could probably make a prototype pretty easily. A battery, some buttons, and a bluefruit[1] should be enough to make one. You would likely need to also write some kind of input translator (Custom android keyboard or so?) to wrap/ convert the value from straight key presses to your combinations (since you want a combination of key presses to give you just one character). 3D print a case, and you're probably all set to go.

I mean, it's likely easier said than done, and would take some time and effort, but it's probably also pretty do-able.

[1]http://www.adafruit.com/blog/2013/09/27/new-product-bluefrui...

[vanderZwan]

Since Arduino can be programmed to function as a keyboard[1], wouldn't that be an easier option? Then you can put the chording logic on the Arduino board and have it function like a plain USB keyboard otherwise as far as the computer is concerned[2] (that's kind of how the Makey Makey[3] works - it's also Arduino based).

[1] http://arduino.cc/en/Reference/KeyboardWrite

[2] http://store.arduino.cc/index.php?main_page=product_info&cPa...

[3] http://www.makeymakey.com/

[mcb3k]

Yeah, you should be able to do that as well. There are a lot of different ways you could make a project like this work, I was just wanting to throw out an example to show that we're empowered to do these kinds of things now. We don't have to wait for some company to come out with a portable, bluetooth chording keyboard anymore, we can do these kinds of things ourselves. I think that is really exciting!