I've been working hard for the past few days on the successor to Simple Alarm: KeepTime. KeepTime has all the same features as Simple Alarm (12- or 24-hour format; month/day/year or day/month/year date format; a custom message; etc.) but also includes a timer and stopwatch.
For now, there's no released version, as I intend to include an update feature soon so users don't have to keep an eye on the repository for new features. That's not to say there will be many updates, but I like to include it just in case.
The lack of a release version unfortunately means you have to build the project yourself in Visual Studio. You can clone the repository on GitHub.