Do you worry that your server is down when you're out of the office? bMonitor can test a server with a variety of protocols, such as ping, FTP, and HTTP. If the connection fails, the phone starts ringing. The tool offers a variety of customization options, including the ability to set how often the phone burns up battery power by testing a server. Too many tests can really wipe out a charge. It's not perfect -- I've found that bMonitor can get mixed up if the network connection is unstable or hogged by another app, leading to a false alarm. But a false alarm is often better than none at all. Price: Free.