Want to know what features your iPhone will be getting with the release of iOS 9 in September? Curious as to whether your device will be compatible? You're in the right place.

Earlier this week, Apple hosted 5000 developers at its Worldwide Developer Conference in San Francisco. Among the announcements were a new version of Mac OS X, a big update to the Apple Watch and the next iteration of its flagship mobile OS that powers the iPhone and iPad, iOS 9.

Here's what you missed.

You Can Probably Run It

If you were able to update your phone to iOS 8, you'll be able to update to iOS 9. That means that users with an iPhone 4S, fourth-generation iPad or fifth-generation iPod Touch or later will be able to install the update, and you won't even need that much free space to install it. The update clocks in at 1.3GB, which is small compared to its predecessor which weighed 4.58GB.

One thing worth mentioning is that iOS 9 gives app developers the choice of simply switching off support for older 32-bit devices that don't use Apple's A7 chip or newer. That means devices older than the iPhone 5S or iPad Air may see certain developers drop support for their devices, but you shouldn't worry too much about it at this stage.

Most developers will want to maximize their reach by targeting as many devices as possible. It's unlikely many will follow through at this stage in the game, but it's certainly a sign of things to come in the next few years.

New & Improved Apps

This year's update includes mostly refinements of what came before, which is generally what Apple does best. As an example of this, gone is the "bury it in a folder" app Newsstand, to be replaced with a Flipboard-esque highly visual app simply titled News, which brings together content from a range of print publications and websites.

Unlike Newsstand, which took the traditional subscription model used by existing publications, News assembles and curates the headlines from various sources and learns more about what you want to read, as you read it. You can also pick specific sources you'd like to follow, and Apple is making it very easy for prospective publishers to sign up, contribute their content and pocket 70% of iAd revenue.

Another app that in dire need of an update is Notes, and iOS 9 turns notes from a simple text editor into a fully-fledged Evernote-wannabe complete with support for to-do checklists, note attachments like photos and maps and even handmade sketches. It doesn't have Evernote's collaborative features, but it does sync over iCloud and allow you to add notes using the share button from any other app.

Maps has also been updated to include public transportation information, which is customized to each city which supports it. Supported cities include London, New York, Berlin, Chicago, and 300 Chinese cities — with more expected to make the cut before September. Search within the app has also been updated to enable you to browse by category — including restaurants, grocery stores and coffee shops.

Passbook was introduced with iOS 6 as a way of keeping your airline tickets, store reward cards and other easily losable bits of paper in readily-accessible digital format. Now that Apple Pay is here, the app has been rebranded as Wallet and is now home to both credit and debit cards (in countries that support Apple Pay) and other passes too. Just double tap your Home button from the lockscreen to access your wallet.

In other news, Apple rebranded their "iOS in the Car" technology to CarPlay at last year's Geneva car show. Now they're announcing that it's going wireless, can be controlled using knobs and buttons and most excitingly will allow developers to create their own apps that can control your car's features.

Improvements to Siri & Spotlight

Every year Siri seems to get a little bit better, and this year the assistant gains the ability to understand even more complex commands and precise search terms. Apple's example of this is given as: "Show me photos from my trip to Aspen in January."

Another interesting feature that many will instantly forget about is the ability to ask Siri to remind you about what you're doing right now — be it an Evernote note, an IFTTT recipe or even a YouTube video. Simply ask Siri to remind you later, or when you get home using a location-based reminder, and you'll get a notification.

Apple's search feature, known as Spotlight, has also been improved with context-aware suggestions. When you pull down on your home screen to reveal the search box, you'll now see suggestions direct from Siri about relevant contacts, apps, local news and nearby amenities depending on the time of day, location and who you've been talking to.

This extends to other OS elements too, and Siri will make context-aware suggestions for music to listen to, people to include in email threads, Calendar events, traffic-aware notifications that let you know when you leave your meeting and will even comb your email for phone numbers to identify incoming calls from unknown contacts.

And though it sounds like your phone will be collecting data in order to provide these intelligent suggestions, Apple has made a big song and dance about the data not being attached to your Apple ID or identifiable credentials. If you want to make use of the new feature, you're going to have to take Timmy's word for it.

The iPad Gets (Proper) Multitasking

A feature banded around on Windows and Android tablets for a while now, the iPad will get true multitasking in the form two apps being used simultaneously, side-by-side. For the record, iOS already has proper multitasking — iOS 8 lets you run two or more apps in the background presently, but iOS 9 introduces three new ways of using them simultaneously (on the iPad at least).

Slide Over allows you to open a second app simply by swiping inwards from the right-edge of the screen. This smaller app looks more like an iPhone app than an iPad app, and you're not able to modify the size it is displayed at. It's great for checking Twitter while browsing the web, but not suited to serious work.

Split View (pictured above) is a far more powerful feature and allows you to use two apps and adjust the border between the two to suit what you're currently doing. At present, the feature only works with Apple's own apps like Safari, Mail and Maps but support will surely be added for third party apps as developers get their hands on iOS 9's new toys. Imagine outlining a document as you write it in Pages, performing web research in Safari while writing a paper or chatting with workmates on Slack while doing anything other than work.

Last of all a Picture in Picture mode allows you to display video from one app while using another. You can drag the video around the screen to position your FaceTime call or YouTube video wherever you want, and even control the video without returning to the app itself.

A Better iPad Keyboard

Further ramping up the iPad's status as a laptop replacement, Apple has turned the QuickType suggestion box into a shortcut bar that appears at the top of the iPad's keyboard, featuring dedicated buttons for cut, copy, paste, formatting controls and even attachments (your QuickType suggestions will still appear in the center).

Another exciting feature for those who spend a lot of time typing on their iPad is the ability to use the screen like a laptop touchpad and control the cursor using a two-finger swipe. The feature isn't limited to just selecting text, though that's arguably what has many most excited, marrying the convenience of a touch screen input with the accuracy of a touchpad.

Finally if you really are an iPad typist, you've probably got a dedicated keyboard, and now you can use that keyboard to issue desktop-like commands to your iPad, including command+c for copy and command+tab for switching between apps as you would on your Mac or Windows PC. Developers will be able to implement their own custom shortcuts too.

Better Security Measures

Two-factor authentication (2FA) for iCloud is coming, which will integrate with your iOS devices on an OS-level rather than relying on text messaging or email. 2FA uses something you know (a password) and something you own (your iOS device) in order to keep your iCloud account secured, and we'd urge you start using it right away.

Another tweak to security comes in the form of six-digit passcodes, meaning there are now 999,999 potential codes to crack, up from 9999 under the current system. Was this a response to that iPhone passcode cracking machine that surfaced earlier this year? Probably, and if you bought one you only have about three months left to use it.

Under The Hood Improvements

There are hundreds more improvements under the hood, but you probably won't notice them. One area Apple is hoping you'll notice improvements is in the power usage and battery life department. The company is even suggesting that by upgrading to iOS 9 you'll get an additional hour of battery life out of your device (though it's not clear whether that's standby time or not).

A more accurate number would depend on your connection type, GPS activity, screen brightness and other factors; but the point here is that Apple is trying to make iOS more efficient for everyone, not just those buying brand new devices.

As previously mentioned, iOS 9 is also promising less pain when it comes to updates, citing an update size of only 1.3GB for iOS 9 (down from 4.58GB last year). It's not clear yet whether that means iOS 9 will leave you with more free space than its predecessor, but it should make updating to the latest version far more painless on the iPhone 4S and 8GB iPhone 5C.

Finally... It's Easier to Switch From Android

While this isn't strictly an iOS feature, it definitely affects iOS users — Apple is releasing an Android app on Google's Play Store designed to make it easier to switch from Android to iOS. The app gathers your contacts, message history, photos and a heap more information and prepares it for migration to a new iPhone.

The App Store will try and suggest equivalent free apps to those you're already using, and any paid apps that you haven't bought yet on iOS are added to your wish list.

Coming September

You'll have to wait till September (or enroll in Apple's developer program at $99 to join the beta) in order to experience iOS 9 for yourself. iOS 7 and 8 were released on September 18 and 17 respectively, which gives you some idea when to expect iOS 9. And if you hadn't guessed already, it's a free update, as ever.

What are you most looking forward to from iOS 9?