Description:
Basically the application blinks the device LED every few seconds. The idea is to have some notification that the device is still alive.

Main features:
Blink the LED every few seconds. If the battery level is below the threshold, orange led is blinking otherwise the green on is used.
If the radio is turned off or there is no signal, another orange blink occurs (in addition to the regular one).When the phone is charging the orange LED lights constantly, every few seconds a sequence of green blinks according to the batter level occurs (20-40% - 1 blink, 40-60% - 2 blinks, 60-80% - 3 blinks and 80-100% - 4 blinks). If the battery is fully charged - the green led lights constantly.
Blink interval and length can be set via the registry. Different blink interval for idle mode and when notification exists (new message/missed call).
Running the link once starts the application, on blink sequence occurs. Running the link again runs the configuration application from which the service can be closed.
Blink sequence for the normal , low battery, no-signal, new message (Voice/SMS/EMail), Missed calls, wireless status (bluetooth and wifi), on and off blink sequences can be set via the registry.
Tested successfully on: HTC HD2 (Leo), HTC TD2 (Topaz), HTC Touch HD (Blackstone). But might work on other devices (please let me know if it works on other devices as well...).If you like this project, please consider donate to the developer.

Update Description:
v1.4 (14-05-2011):
- Rewrote the service project in c++ (Now the service requires significantly less memory when running).
- Added ability to vibrate (see second post for further information).
- Added ability to play a wav file in the sequence (see second post for further information).
- Added sequences for "Appointment" and "New MMS".
- Blinker now uses only the WM notification method.
- Removed the "Use WM Notification" as it is no longer required.
- Removed the "SMS Store" setting as it is no longer required.
- Fixed issue where in lower resolution devices a scroll bar did not appear in the settings application.
- Added "Advanced" tab in the settings application.
- Added a "Wakeup notification" - this option will force the device to wake every couple of seconds. This should solve the "unattended issue" - but might affect the battery drain. This feature can be turned on under the "advanced" tab in the settings application.
- Hibernates when no blinking is required.
- Changed "AllowUnattendedMode" to "ForceUnattendedMode" and added a checkbox to control this value under the "advanced" tab.

v1.3 (06-04-2011):
- Blinker can now use the notification system instead of directly check the Stores (thanks peterpan911 for the tip). This can be configured in the setting, under "Use WM Notifications".
- Blinker can be configured to load on startup from the settings window.
- Improved performance (thanks p50kombi)
- Some minor interface improvement to the settings dialog.

v1.2 (10-02-2011):
- Added possibility to set the green/orange LED id.
- Added possibility to set the SMS store name.
- Improved error handling in case SMS store is not found.

v1.1 (03-12-2010):
- Added notifications for new message (SMS/EMail/Voice), missed calls and wireless status.
- Added possibility to blink the keypad light as-well.
- Added separate delay interval on new message or missed call.
- Tweaked the unattended mode. The halting problem still exists, but it seems better now.
- Added a configuration utility. To run it press the Blinker shortcut again (after blinker is already running).

v1.0 (06-11-2010):
- Initial release.