"Uptime" addon

[litesung]

Is there an addon that records how long you have been logged online since login of character (entering game world)?

I also saw something on someone's rainmeter desktop that had this and it said
"your computer has been online for X days X hours and X minutes, are you ready for a break?" but I couldn't really find that plugin. It gave me an idea to see if anyone would be able to make this addon for WoW.

Also, does anyone know where I can find rainmeter skins that provide this feature?