It will also feature open APIs as well as back-end software including HomeKit and HealthKit. The installation of iOS 8 will take nearly 5GB to 7GB of your storage. So, the users who have 8GB or 16GB versions of iPhone or iPad should give a second thought before moving ahead as you may need to delete lots of things. Health apps are the most significant part of the operating system as the company has been promoting it since long. The featured health app in the operating system acts as an interactive dashboard that enables users to check out vitals, including calories burnt and distance walked, as a result of its motion sensor. The app also has an ability to extract your health data from several fitness apps and health fitness accessory makers. iCloud Drive is also one of the most attractive feature of the operating system and is an answer to Dropbox. It enables users to save all their files on your Mac, PC, iPad, and iPhone at one place. However, the users may not be able to use some continuity features as it requires OS 10.10 Yosemite, which will not be available until October.