Apple has just seeded the fourth beta of iOS 9.1 to developers. This comes one week after the last build. iOS 9.1 brings support for the new features that come with the iPad Pro, new emoji figures, and bug fixes.
Apple has also seeded the third beta of tvOS to those who were able to get a new Apple TV.
Developers can get the latest beta of iOS from Settings > General > Software update > iOS 9.1 Beta 4.