title: Measuring keyboard typing speed, key-press rate in Android
body: <p>I would like to create an app which runs continuously in the background and does the following:
  - When user opens a keybaord to type, timer starts and I log start/end time and number of characters (key-presses) typed in a given go.
  I just need ideas on this (point me to an API or something) - how should I go about this - ideas?</p>