Use Power Monitor Pro to be alerted if your building power fails. Simply connect your phone to the charger plugged into a wall outlet and start monitoring.

*** Get this app now at the introductory low price ***

Useful for home owners if you want to be woken up at night if your power fails.
System administrators can use this in your office to track down mysterious power problems.
You can even use this to sound an alarm if someone tries to take your phone while you are not looking!

Power Monitor Pro will log when you start and stop monitoring, as well as log every time the power goes out or comes back on. You can email this log for centralized record keeping as well. Power Monitor Pro also has an "alarm delay" feature to not sound the alarm for power outages shorter than a customizable time period. You can also turn off the alarm to just log power failures for later analysis.