My wife likes to run early in the morning, but her running routine alternates ten minutes of running with a one-minute walk-break. If you're out there in the darkness of pre-dawn, how do you figure out when to go from one to the other?
With your iPhone, of course!
Nancy wasn't happy with the simple timer included as one of the base apps, though it's served me well as a one-time alarm. So she searched the App Store and found Routine Timer (Practiphone LLC, $2.99 limited time price they say).
With this app, she starts with a walk of five minutes, just to get the blood going. When it's time to run, she's got a metal gong sounding.