This is more specific to UX. UI is simple and plain. My mom asked me to teach her how to type after having learnt mouse-clicks and all. Now the problem was

• She was slow. (It's not her fault. She is a great multitasker in kitchen but she was typing for the first time.)
• She sometimes didn't understand what she typed wrong .
• I have to interrupt her in between for tiny mistakes like you pressed spacebar key twice.
• In short I have to be beside her all the time for teaching her typing.

So I found a solution and that was this small web app. She was very happy. Me too :) because now I don't have to be beside her all the time. So now ...

• Whenever she typed any character wrong she was immediately informed by the arrow which told her the exact location of mistake
• On completion of each line a sound was played which meant you typed that line correctly
• Colors changing trick also worked

Try another browser. Canvas doesn't work