1. Health hub
The biggest new addition that iOS 8 will bring might turn out to be the new Health application. The app collects your health and fitness data, such as daily activities, a calorie counter, heart rate, blood pressure, sleep patterns, and so on. The data collection is no less interesting, too, as some of it will come from external accessories, like Nike's armbands, and some of it will come straight from the Mayo Clinic. That's right, Apple has developed Health in conjunction with one of the best clinics in the US, and the convergence will allow you to pull your medical records, lab results, and illness status, as well as check your morning run statistics, all from one Health hub.
2. Interactive notifications and third-party widgets
You can now reply to a text message or an email, Facebook or a Twitter post, directly from the pull-down notification center in iOS 8, without leaving the app you are currently in. Those interactive notifications have been rumored for a while before the iOS 8 announcement, and now they are here. Not only that, but the new Notification Center is being opened up to third-party widgets.
The new system in iOS 8 was demonstrated with an eBay widget in the pull-down notification center, which informed the user on the progress of a guitar bidding process. You can place your bid straight from the notification center, too, which adds interactive elements to the widget experience, and increases their usage tremendously. It is not yet clear whether developers will have to go through a vetting process, before their widgets make it in the notification center of your iPhone and iPad, or it's going to be the Wild Wild Widget land there, but the new system is a very welcome and uncharacteristic step, which is likely to earn Apple's a lot of user accolades.
3. Frequent Contacts get to the Multitasking View
When you tap twice on the Home button, the iOS 8 device takes you directly to the multitasking view. Not only can you preview the apps that are running in the background, but you can access your most frequently used contacts directly from the multitasking view, too.
4. QuickType keyboard
The "quick" term in QuickType stands for text predictions. The new iOS 8 keyboard will suggest whole phrases, based on what you have typed, not only words. For example, on a message that asks "Want to go for a dinner and a movie," it will give you canned answer options like "What do you have planned?" QuickType will also get better with time, by learning your vocabulary, and adjusting to your typing habits.
5. Third-party keyboards
Yep, you won't be left only with the new QuickType keyboard on the eventual big-screen iPhone 6. Third-party keyboards will also be able to make a cameo, which bodes well for all you Swype-loving aficionados.
6. Family Sharing
You can now make your family the nuclear group it indeed is, and iOS 8 can automatically share photos, calendar events, reminder alerts, etc., among them. Family sharing allows you to share your apps, music, movies and TV shows with one another, and even your iTunes account. On the plus side, kids will need permission to buy apps from their parents, as you can define their devices with Family Sharing, and even use the Find my iPhone to track them at all times.
7. Group messaging
You can now name the threads, add and remove participants, set personalized Do Not Disturbs, and leave threads. Not only that, but you can easily record and send a voice text, stream a video, or share your location mid-convo, and all can be done within the new messaging app.
The new iOS 8 search function now enables you to search for almost everything, like news, apps installed on the device, points of interest, and even iTunes songs - all from the Spotlight field.
9. Always-on Siri, powered by Shazam
Siri becomes an always-on personal butler, awaken with the "Hey, Siri!" hotword. Siri now also features the Shazam song recognition service, and lets you purchase content from iTunes with your voice. In iOS 8 it flaunts streaming voice recognition, and 22 new dictation languages.
The Photos app is receiving the next "massive" update in iOS 8. You can now store more photos in the cloud than you can have in your device alone, thanks to the new iCloud Drive service. The so-called Smart Editing has become richer, easier, and will now sync edited photos across devices.
The photos and videos you take are stored in iCloud Drive in their full resolution and glory. The first 5 GB of storage there are absolutely free, and you can get 20 GB for $0.99 per month, or go all the way up to 1TB.
11. iCloud Drive
While not strictly an iOS feature, the new iCloud Drive is a Dropbox-like (or Google Drive-like) service for storing and sharing of files and multimedia, as well as syncing them across OS X, iOS, and even Windows devices. Each app that works with iCloud Drive will sport its own folder inside the Drive's interface, too. As mentioned, pricing starts from free for the first five gigs, and you can hit up to 1 TB of fluffy storage.
12. New Mail features and Gestures control
Mail might not be the most used communication application anymore, but that didn't prevent Apple to intro a few enhancements, like the ability to send up to 5 GB attachments via iCloud Drive, and gesture navigation. With a swipe gesture you can now send an email to the trash, flag it, or see more details about it.
13. New design and animations
Apple has streamlined the iOS 8 interface even further, compared to iOS 7, and brought the number of animations to a minimum across the board, which should bode well for older, slower devices. In addition, numerous new tweaks to the way things are done have popped up, helping the iOS 8 users navigate the stock apps, and the interface.
Apple has learned its lesson, and improved on the Maps app with a lot of under-the-hood enhancements. That goes especially for users in China, where a massive amount of new map data has been uploaded, and vector ones at that.
The new Handoff extension to AirDrop means that you'll be able to start an email on any Apple device and pick up where you left off on another Apple device. The feature will work with Apple Mail, messaging through iMessage, tab syncing through Safari, and it will even allow you to make and receive calls on your Mac, while the call is run through your iPhone as a relay. Handoff will make it very easy to connect your Mac to an automatic hotspot created on your iPhone, too.