The OnePlus One has just received its update to Cyanogen 13.1. This update includes a feature which allows the manufacturer to Mod parts of the rom it did not have access to before. The big change they have made for the OnePlus One is the addition of some Microsoft features.
You are now able to make Skype calls from the phone app, Cortana has been added, hyperlapse brings time lapse videos to the camera app, and more. There was one more feature added that does not pertain to Microsoft and that is a feature which shows you trending tweets from your lock screen.