Your iPhone can quietly monitor your balance every time you go for a walk, and warn you if something changes. Here's how to set it up. I want to tell you about a feature that's been sitting inside your iPhone; completely free, no extra apps, no subscriptions, that most people have absolutely no idea exists. It's called Walking Steadiness. And if you're over 55, or you have a parent or someone you care about who is, this might be one of the most quietly important things your p