Nightstand Central Free 3.0..
the author of this app says:
Nightstand Central Free turns your iPhone or iPod touch into a high quality alarm clock with current weather information and customizable wallpaper. It also supports iOS 4 background alarms. You get many of the great features of Nightstand Central, but for free.
Compatible with iPhone, iPod touch, and iPad. Requires iOS 3.1 or later.