It's a nice application. The only (very serious) problem is that it relies on a modified version of the "top" UNIX utility to obtain information. And the "top" utility only works correctly when running as root. Therefor the password request at first launch of XMonitor: it's required to set the setuid bit and the owner of the pseudo "top" tool to root. Concretly, you have something inside the application package that belongs to root with restrictive privileges. So you cannot copy the application elsewhere (the Finder will produce an error)...