Description: Kronometer is the KDE stopwatch app. According to the KDE website, it "is part of the KDE Extragear collection, within the Utils sub-module."
Why: Currently GNOME clocks is in the repository but (a) it doesn't integrate as well with KDE, and (b) it isn't as configurable as Kronometer.
License: It is open source, GPLv2+
Who will use it: I've built the package on my local machine and certainly use it all the time. I think a stopwatch is something many people will use, especially people using Solus KDE edition who want a native app and not a poorly integrated GTK+ app.
I submitted a patch at D8917 but Joshua directed me get a task approved first. Sorry for the inconvenience, I'll try to follow better decorum in the future.