Latest Windows 10 Mobile build shows how many rings your caller waited before hanging up25
With this scam, someone calls and hangs up quickly before the call goes to voice mail. When you see the unanswered call notification, you dial the number, unaware that you've called a service that charges a ton of money for the call. By knowing if a caller waited only one ring before hanging up, it might alert you to the scam. This might prevent you from returning the call, and paying a huge sum of money for a premium service you didn't want to use.
Those seeing this feature on build 10572 had to revert back to Windows Phone 8.1 before receiving this version of the OS. That's because of an issue that prevents those testing Windows 10 Mobile, from updating to the latest build. Build 10575 is expected next, and will reportedly fix this problem.