Microsoft has made Windows 10 Mobile Preview build 10512 available to Windows Insiders on the Fast update. That build has over 2,000 bug fixes compared to the last preview version, 10166, which was released over a month ago. Here's the list of certain improvements, as posted by Microsoft's Windows Insider head Gabriel Aul: General improvement in overall stability and performance. You can now set the Lock screen and background image from within the Photos app. We fixed an issue where apps installed on SD cards weren't working after a reboot. We have improved Latvian and Chinese inputs. We have made improvements to the Kid's Corner tile layout. We have improved reliability of Data Sense notifications. Modified Shape Writing algorithm to be less aggressive in suggesting contact names over common words. Resolved an issue where Camera would not launch when the phone was locked. We fixed an issue where notifications for incoming text messages weren't appearing. We fixed an issue where the touch screen wouldn't be responsive after ending a phone call on some devices. And we fixed an issue where folder tiles have obviously overlapping text.