It sounds you need to read each tool's download/usage notes carefully... They always explain how to activate the tool and what 'helper' files are needed etc. For example 'CurviLoft' is an Extension and needs activating [once] from the Preferences menu, you then need to active its Toolbar etc... However, it still won't work unless you have the 'LibFredo...' helper/folder installed, as the download page says [and there is a link to it too]...