If you are running LogViewPlus from the notification area, the application will only be shown in the taskbar when needed. To remove the application from the taskbar, simply close it using Alt+F4, or the window close button in the upper right corner, or click the icon in the notification area. This will not shut down the application, it just hides it by removing it from the taskbar.
To restore LogViewPlus, click the icon in the notification area. LogViewPlus will then appear in the taskbar.
To fully exit the application, you need to right click on the notification icon and select 'Exit'.
Hope that helps,