Previewed at WWDC, launching in the fall.
Apple Seeds Second Beta of iOS 10.2.1 to Developers
Registered developers can download the second iOS 10.2.1 beta from the Apple Developer Center or over-the-air with the proper configuration profile installed.
It isn't known what features are included in iOS 10.2.1, but as a minor 10.2.x update, it appears to focus on bug fixes and performance improvements rather than major outward-facing changes.
No new features were discovered in the first iOS 10.2.1 beta, but we'll update this post if any changes are found in the second beta.
iOS 10.2.1 follows the release of iOS 10.2, a significant update that brought Unicode 9 emoji, a new TV app, Messages Screen Effects, Music improvements, and a whole slew of bug fixes.