Apple revealed CloudKit for developers enabling iCloud integration with third party apps.

Healthkit

As predicted, Apple revealed a health application dubbed Healthkit.
Apple kicked off its health and fitness thing last year with the launch of the iPhone 5s and its built in M7 coprocessor – an “always on” companion chip designed to log, record and track activity. The M7 was opened to developers and since launch we’ve seen a whole host of fitness applications leverage the chip.
But the M7 was just the tip of the iceberg – it laid the foundation and got users used to having their activity tracked by their iPhone. With the advent of iOS 8, we’re about to see the rollout of Apple’s masterplan for how health and fitness will be tracked, monitored and, most importantly, analyzed using the company's iPhone handsets.
Apple’s HealthKit makes sense of all the data and pushes it into an iOS application called Health. Like Passbook, Health is a card-based native application that displays pertinent information about certain metrics (calories burned) and activity (how many steps you’ve taken).
Apple’s HealthKit API essentially uses Units and Quantities to monitor activity, body metrics and things like your age, weight and location. It can also do things like Blood pressure and count steps or distance covered during a run or bike ride. HealthKit is open to developers to use inside their own applications, too, so expect to see A LOT of apps launched in its wake.
Apple confirmed Nike would be producing one of the first devices that truly takes advantage of HealthKit. Likely a FuelBand or sorts, the Nike wearable will be just one of an entire myriad of wearable devices that’ll be released following the launch of Apple’s iPhone 6 later this year.
And then of course there's Apple's iWatch...

Sharing

Craig Federighi explained Apple's new sharing features, saying, "Once you've set up your family as a unit, you automatically share photos, calendars, reminders, or find my friends."


"In the home we're used to sharing physical media, but increasingly our media is in our devices. Now you can get at not just your purchases, but the purchases of everyone in your family." It works with up to six family members...on one credit card. Sounds risky, but it means parents get a prompt to approve new purchases.
Photo sharing has also been enhanced:
"Now we're bringing together photos with iCloud — every photo you take available on all your devices."


But it's not just sharing either, Apple is enabling extensive photo editing tools which work across devices. Copies of your photos are stored in the cloud, so even if  you edit one with the built in tools the original will remain. You can do this on iPad or iPhone and it uses your iCloud account, meaning you've got 5GB free but more storage space will cost a subscription fee.

Siri

Siri has been tweaked so that you don't need to touch the phone, just start talking and it'll respond. It also now features integrated Shazam song recognition and you can prompt it to purchase iTunes content.
Another cool hint was Apple's revelation that Siri tools will allow developers to integrate the assistant with their apps. Apple gave an example where you might be able to say "get ready for bed" and an app synced to your house lights and doors might turn all the lights off and lock the house.

Apps & Widgets

Following Apple's main announcement of iOS 8, Craig Federighi went on to talk about the improvements for devs. One or two gems for the consumer came out of this talk, however.


First of all, Apple has developed what it calls "Extensibility", a development tool which allows apps to extend their services to other apps. Developers can create app extensions which live in "app sandboxes" where apps can interact. Primarily this will allow more sharing extensions, so you could, for example, use Pinterest from inside Apple's Photos application.
The other big change is the introduction of Widgets. Apparently these have been in development since iOS 2! Widgets are added to the notification centre and Safari. Apple is also enabling third-party keyboards just like Android - Swype on iOS!
And now, thanks to Phillips, we have a pretty good idea about what “widgets” will look like inside iOS 8. In a tweet, posted over the weekend, Phillips debuted a widget for its Hue service, which you can see in all its glory below.
As you can see the widget sits in the notifications center. From here, the widget – thanks to Extensibility – can communicate with the app and pull real-time data into the notification center without you ever opening the Hue application itself.
This is just one example of what can be done with widgets in iOS 8. Philips didn’t say much about functionality in the tweet, although it’ll be very interesting to see how other manufacturers, Sonos, for instance, leverage the new capabilities.
Apple also explained its new "Metal" developer API, a set of tools designed to unlock the power of the A7 chip for games developers. It will essentially take gaming on iOS to the next level with incredible physics and graphics.

Touch ID

This is the BIG one – money wise. TouchID is now open to developers meaning every retailer under the sun can begin accepting payments via iPhone and iPads, meaning come-autumn you’ll be able to use your iPhone to make payments for goods and services online and in-store.


And people seem to love TouchID, too. According to data from Apple, passcode adoption skyrocketed from 50% to over 83%, following the release of the iPhone 5s and its TouchID sensor. Expect TouchID-enabled apps from the likes of Amazon, Google, Mint, Natwest, Starbucks, Mint, and PayPal to coincide with the release of iOS 8 later this year.

Quick Access Contacts 

Apple revamped multitasking in iOS 7, adding in a new carousal view which you access by double tapping the home button to bring up all your open apps. And inside iOS 8 there’s another useful addition to the hub: recent contacts (they’re stationed directly above your already-open applications, as you can see below).

Better Spotlight

Wikipedia, the Apple App Store and iTunes have all been included inside iOS 8’s universal search function, Spotlight. The search function is accessed in exactly the same way it was before (drag down on the homescreen) but is now exactly pretty useful when looking for new albums, content and applications – or when you’re at the pub quiz.

Hello, Weather Channel!

Bad news, Yahoo! Your weather service just got sacked. Inside iOS 8 Apple has switched its weather allegiance to The Weather Channel. Why this happened is unclear: it could be to do with price, service quality or integration. Your guess is as good as ours!

Best Of The Rest

There’s a load of other features coming in iOS 8 which Apple just didn’t have the time to explain whilst the keynote was going on. At the moment there’s not that much known about some of these features but most are self explanatory.
You’ll finally be getting battery usage per-app stats just like Android, it helps you to know which apps use up the most power and therefore you can take steps to save some much needed battery life.
iBooks is becoming fully integrated with a brand new auto night mode whilst Safari will also get a Private Browsing option for each individual tab.
A Tips app is also incoming which we assume means tips and tricks on how to use your iOS device a little better. There’s also Wi-Fi calling support meaning you won’t need to eat up all that data just to do some internet calls.