“Hey, can I call you?” I bet millions send this text every day. It’s common etiquette. You text first and see whether someone is busy. If you get a “Sure,” or “Y,” or “K,” you can ring that person up.

Last week, we shared a list of iPhone safety tools that every iPhone owner should know about, from Emergency SOS and Medical ID to Safety Check and Check In. MacRumors readers had more suggestions on ...