Apple's iOS 9, which has been codenamed Monarch, will be unveiled on the company's annual Worldwide Developers Conference (WWDC), which will be held this year on June 8 to June 12 in San Francisco.

iOS 9 is shaping up to be even more significant compared to the previous major release of Apple's mobile operating system, and here is what we know of it so far.

New typeface similar to Apple Watch

Apple is planning to utilize the new system font that was developed for the Apple Watch, expanding the usage of the typeface to iPhones and iPads. The San Francisco font is expected to replace the Helvetica Neue font that Apple started using in 2013 with the release of iOS 7.

App for smart home devices

One of the new things expected to be included in iOS 9 is a new Home app, which will allow users to manage the smart home devices in their households.

In last year's WWDC, Apple introduced the HomeKit, which allows users to configure, control and communicate with smart home devices. According to rumors, the Home app will serve as a continuation of HomeKit and will give users more control over how they manage their connected home.

Optimization for older devices

Apple is also reportedly working to make iOS 9 more compatible with devices that are using the company's old A5 processor, which includes the iPhone 4S and the first version of the iPad Mini.

In previous major releases of iOS, Apple developed complete versions of the operating systems for older devices and then removed the features that will decrease the performance of the devices. This strategy has not worked well for certain users, as evidenced by the uproar of users caused by the rollout of iOS 7 which made iPhone 4 devices very slow and unstable.

For iOS 9, sources reveal that Apple is working on a core version that is optimized to be able to run efficiently for iOS devices as old as the iPhone 4S, and then the new features will then be added one by one as versions for newer and more advanced devices are being developed.

Anti-jailbreaking measures

It is expected that iOS 9 will include a feature known as Rootless, which insiders claim will largely prevent jailbreaking activities. Rootless will be able to prevent even users with administrative access from being able to access certain files. According to sources, Rootless will also improve protection against malware and the security of the private data of users.

Focus on quality and stability

The engineers of Apple have finally been able to pressure the executives of the company for iOS 9 to focus more on quality and stability, as opposed to focusing on releasing new features. While there will still be new features for iOS 9, the list will not be as long as initially planned by Apple's top brass.