it doesn't show up when you try to add it to your screen? If it is just a widget, then it may not show in your app drawer
Yep, if it is a widget only (live wall papers also) you can added it to the home screen by long pressing and then adding a widget, it should show up in this widget list.
JP
these clocks are driving me crazy. The clock app, from rooting, shows only in its own screen. The widget(digiClock) only has a setting icon, but I can't find the widget itself