Sonar has now been updated to version 5
Sonar5 takes the principles of previous versions of Sonar and improves them.
This version can be used either installed on your hard disk - when it stores it's configuration data in your user area, or stand alone on a pen drive, when it stores the configuration on the pen drive.
Either through the icon in the Notification area of your taskbar or through the relevant keyboard shortcut, you can access the Settings dialogue (CTRL + ALT + A) where you can change the shape to either a circle or a square, alter the diameter of the shape, alter the width of the line and change the colour.
Whilst running, the application can be hidden and restored by clicking on Show/Hide or by using CTRL+ALT+S.
Finally, this version of Sonar sits above the menu's in Windows, providing identification anywhere.
As usual, available for free download at http://www.fxc.btinternet.co.uk