ver 1.8: automatic launch on device-booting
ver 1.4: added "reassociate." in almost devices, it might be better
ver 1.3: minor modification, frequency of accidental terminations may be reduced.
When the screen light-on, this software make wifi disable and then do enable automatically.
With some device (esp. android 1.5, 1.6), it might fix wifi reconnect problem.