The customizable clock faces alone make this a better option than your built-in clock app, not to mention alarm options ranging from birdsong to blood-curdling screams or whatever's in your iTunes library. For inveterate oversleepers, the app can force you to solve a math puzzle before the alarm shuts off.
WIRED Virtually snooze-proof. Add local weather to any clock face.
TIRED Susceptible to digital hiccups, like all software timekeepers.