I have emerged simpleagenda. Everything went on smoothly, no errors or warnings appeared. emerge --search simpleagenda shows that version 0.43 of the package is installed.
However, I cannot find it in any FXCE menus and there is no simpleagenda command in shell. Moreover, there are no simpleagenda folder in /usr/share/doc and no man page for it. Application Finder also does not see it. Does anybody know how one can start this extremely humble program?