The fourth beta version of iOS 9.1 is released to fix bugs which appeared in 9.1. It also introduced some new features, such as, more emoji like taco, cheese wedges, middle finger, burrito, unicorn heads and many more. It also has new message option available at the app setting, which will allow users to disable contacts photos.
The latest Beta comes with four new wallpapers. The latest build is now available to developers as well as public beta testers. Both the operating system can be downloaded from Apple Developer Center and over the air update.
It is not known when iOS 9.1 will be available to the public. However, chances are that it might come in late October.
Download iOS 9.1 beta 4 Pre-release from here.