Hi!

If you would like to stop and later restart UWS service, along with all registered web apps, you may use following commands"
C:\>net stop "UltiDev Web Server Pro"
C:\>net start "UltiDev Web Server Pro"
Please keep in mind that it will stop all applications, not just one.

If all you need is to take an application offline, you could unregister it, and then re-reigster it. This may be easier than you think, because when an application is unregistered, it's previous registration settings don't get actually deleted. Instead, mainly to facilitate web app upgrades, if you on application registration you specify only appID and physical path, all other previous application settings will be retained on registration. For example:
C:\Program Files\UltiDev\Web Server>UWS.RegApp.exe /u /appid:{F8563989-47D5-4D40-8170-5138242F793D}
C:\Program Files\UltiDev\Web Server>UWS.RegApp.exe /r /appid:{F8563989-47D5-4D40-8170-5138242F793D} /path="C:\Program Files\UltiDev\Web Server\Redirector"
This method is much less disruptive for other running applications.

Regarding documentation, we don't have a book, but this collection of posts is a very good of articles covering just about every aspect of UWS usage, from both software developer and operations perspectives.

Best regards,
UltiDev Team.