This is a very simple module that lets you type *Uptime to see how long it was since you booted the system. You may wish to put it in !Boot.Choices.Boot.PreDesk so that it starts on boot.
You can download Uptime for free by clicking on the green arrow below. It is also available through PackMan.
The BSD-licensed source is also available below. I would appreciate it if any changes were shared with me so that everyone has access to a "definitive" version.
Requires RISC OS 3.1 or later
Source for Version 1.00