Today Microsoft Announced First Redstone build for #Windows10Mobiles ,This Build is right now Available only for selected Devices. Some Weeks ago Microsoft's "Gabe Aul " Posted on Microsoft blog While Announcing Forth PC build:
" Today we deliver our 4th PC preview build, and are nearly ready to start sharing new preview builds for Mobile as well. We will start by making these builds available to devices that shipped with Windows 10 Mobile – the 950, 950XL, and 550 – and expand from there as we release Windows 10 Mobile to other devices "
Now Today Microsoft Announced First Redstone Build for Windows10Mobile With This Note :
" As I mentioned a couple of weeks ago, initially we’ll make new builds from our Development Branch available only to devices that shipped with Windows 10 Mobile. Currently this includes the Lumia 950, 950 XL, 650, 550, and Xiaomi Mi4. We plan to expand from there as we release Windows 10 Mobile to other devices "
If your Device is not in list them stay On Redstone Build will be live for you too SOON.