Apple issues fourth public & developer betas of iOS 10.1 with Portrait photos for iPhone 7 Plus

Developers already on the 10.1 track can download the new beta as an over-the-air update. Otherwise, they'll have to go to Apple's developer portal to download it. Everyone else must be registered with Apple's Beta Software Program.

It's not clear what changes are in the new code, but Apple is likely extremely close to finishing the update, since it rarely issues more than four betas for a point release, if that many.

iOS 10.1 is mostly expected to clean up bugs missed in 10.0.2 and 10.0.3. Among these are problems with CallKit, preventing call-directory extensions from working reliably.

The main feature, though, will be a promised Portrait mode for the iPhone 7 Plus. The technology takes advantage of the Plus' twin cameras, identifying a subject then artificially blurring the background to simulate bokeh.