smart pen that vibrates when you make spelling error

German inventors have developed a new hi-tech pen that gently vibrates every time it senses a spelling mistake or sloppy handwriting. Lernstift is a regular pen with real ink, but inside is a special motion sensor and a small battery-powered Linux computer with a WiFi chip. Together those parts allow the pen to recognise specific movements, letter shapes and know a wide assortment of words. If it senses bad letter formation or messy handwriting, it will vibrate. Users can choose between two functions: Calligraphy Mode - pointing out flaws of form and legibility or Orthography Mode - recognising words and comparing the word to a language database. If the word isn't recognised it will vibrate, according to Daniel Kaesmacher, the 33-year-old co-founder of Lernstift from Munich. The other co-founder Falk Wolsky, 36, had the idea for the pen last year while his 10-year-old son was doing his homework. "His son had been struggling with his work and staying focused and Falk thought there should be a pen that gives him some sort of signal so he stays focused," Kaesmacher said. After a year and a half in development, the founders have now brought Lernstift to Kickstarter to begin raising money and gauging interest