This was the android app we did at DROIDCON 2013 hackathon , winning a second place(Samsung galaxy tab 3). This app is based on sony smartwatch 2 . So , you wear the watch , you connect it to your device(tab or a phone) and then you draw something in the air , lets say its a square . That square will appear in your device. You draw anything in the air , wearing that sony smartwatch , it will appear in your device . You can watch the demo below