This article, "What we give away when we log on to a public Wi-Fi network", demonstrates how dangerous it is for you to turn on Wi-fi on your phone. It advertises the name of every network it has connected to. And will connect to any network named, for example, “Starbucks”, even if you are not near a Starbucks.
I know you can turn this off when you are in range of a network by opening the Wi-Fi settings tab, clicking a few times and then checking “Forget Network.” But it doesn’t seem like there is a tool for managing these in bulk.
I was wondering if there are any tools—built-in or otherwise—for manually removing networks from the auto-join list.
Mac OS X for example allows you to add/delete/reorder networks: