When the iPhone launched, the world of mobile phone technology started changing immediately. Smartphones were the domain of high-powered businessmen and arch gadget lovers at the time, in part because of price, in part because their utilitarian looks and confusing interfaces didn't appeal to many who didn't need their advanced features.
But the iPhone managed to merge the power of smartphones with the universal, easy-to-understand interface and attractive design that most people want from a phone.
Here in 2013, the iPhone offers hundreds of thousands of apps that make just about any task user-friendly, and has some of the most advanced technology on the market. But it's important to remember that it didn't happen overnight.
There was no App Store until a year after the iPhone launched, and certainly no Retina display. And it's amazing to think that the iPhone 5 has 4G mobile broadband, while the original in 2007 didn't even have 3G.
In just five years, Apple's iPhone has become almost unrecognisable when it comes to the technology that sits inside it, and even the outside features some incredible enhancements, despite looking a lot like the original. And now that mobile technology is the most prominent area of research and development for many companies, we are now only going to see the pace increase from now on.
But what does this mean for the future of the iPhone? Incredible leaps like the inclusion of Multi-Touch don't come around very often, but there are other ways that the iPhone will improve over time. Small advances in areas that seem boring add up to making each new iPhone the best yet, but there are still blockbusting features that just aren't ready yet, here in 2012.
The important thing is that these developments aren't just science fiction: it's nearly all technology that's being finalised, or is being actively researched and developed. Some of the time predictions might prove to be ambitious, or technologies might arrive quicker than anticipated, but it all has potential to be real.
And though we're only talking about the iPhone here and not the iPad - the technology used in them is very similar, so just about all of these developments will improve both devices. So join us in the Tap! Time Machine as we travel to see the iPhone as it will appear a few years down the line with technology that's coming about right now, and we'll also fire off into the near-distant future, looking at how the next few decades will shape and change Apple's devices.
2014 - iPhone 6
1. New camera technology
Early in its life, the iPhone was always on the back foot when it came to the camera. Apple only really got serious about it with the iPhone 4, and now it's one of the most talked-about features in each iteration. Though the iPhone 5 mostly made behind-the-scenes tweaks, such as better image processing, future iPhones will be able to go further.
Sony is known to have supplied Apple's sensors in the past, and in 2013 it will release a new image sensor that packs 13 megapixels into a tiny space without compromising image quality, thanks to a new way of designing the sensor. In fact, it should bring much-improved low-light shooting, because it can capture white pixels as well as red, green and blue. This means future iPhones would also be able to offer HDR recording, for getting maximum detail from videos.
There are other advances in phone cameras, too. Nokia's PureView 808 phone uses a huge 41-megapixel sensor to take great images. The final photos are actually only eight megapixels - what the PureView does is use around five pixels on the sensor for each pixel in the eventual image, and average the colour from those five into the final one, ensuring that it's as accurate as possible. The downside is that image sensors of that size are just too large to include in something as thin as the iPhone.
2. The development of 4G
By the time the iPhone 6 is released, 4G will have developed further than it has now, especially in the UK. For the launch of the iPhone 5, 4G was only available from one network, and in four cities (with more to come soon). By the end of 2013, all the major UK networks should be able to offer 4G connectivity, and the coverage will be up to 70% of the UK.
At the moment, EE (also known as Everything Everywhere - the parent company of Orange and T-Mobile) is the only 4G operator, and it has launched this network on the 1800MHz band in the wireless spectrum. Other operators will have to bid for different parts of the spectrum to launch their own 4G services (except for Three, which will use EE's).
Why is this important? Because the iPhone 5 only supports the 1800MHz band - not the others that will be used in the future. This means that if you buy an iPhone 5, it can only be used for 4G on EE and Three's networks in the UK, even after 2013.
We expect that the next iPhone will offer a much wider range of operating bands as the technology that powers it grows. It's likely that it will work on any 4G network in the UK without problem, much as the iPhone 4, 4S and 5 do on 3G networks.
In the US, there are two different wireless technologies, but it's possible that Apple will even be able to offer a single phone that even works on both of those network types as well.
3. Wi-Fi 802.11ac
Though Apple drastically improved the maximum Wi-Fi connection speeds in the iPhone 5 compared to even just the 4S, the change came about just as the next generation of Wi-Fi technology is being introduced. Its already possible to buy wireless 'AC' (as it's known) routers, and when the technology is integrated into phones and tablets with the kind of technology Apple uses, it's expected to offer local network connection speeds of over 500Mbps - much faster than what's possible now.
The fact that pretty much nobody has a home internet connection fast enough to make full use of this speed might make it seem a little pointless, but there are other purposes beyond surfing the web. It'll mean much higher quality and more reliable video streaming over AirPlay, for example, making playing mirrored games much smoother.
Perhaps most importantly, it will allow for extremely fast wireless data syncing with iTunes - much faster than the new Lightning connector is capable of, for example. If Apple is to ever lose a physical plug connector completely, the high connection speeds of wireless AC will be important for media lovers.
Near-field communication (NFC) is a very short-range wireless technology, designed to make it simple to transfer small amounts of information very quickly and easily. This has made it ideal for use in 'contactless' payment systems - think along the lines of the London Underground's Oyster Cards, where you need only tap a card on a pad to pay the correct amount.
But it's not just about payments - because it can send and receive information in just one tap of your phone, it's great for any ticketing system, so could be used to get into concerts, on the train or even to speed things up in the airport. And when used for payments, it can send your payment information and receive your receipt and any vouchers in the same single tap.
So far, Apple has said that Passbook in iOS does the same things as NFC, but that's not totally accurate. Passbook stores the information, and gets it ready for you when you arrive, but it can only communicate with other equipment by showing a QR code. This means it can only send information, not receive it - but having Passbook and NFC working as one package will offer a great level of flexibility.
NFC has other practical uses as well. It can be used to access a Wi-Fi router instead of a lengthy password, for example, or to pair Bluetooth devices. Like the best new technologies, it has the potential to make life a little simpler, which of course, makes it a natural fit for the iPhone.
5. Secure payment
In the last decade, Apple has spread into all sorts of areas people wouldn't once have expected to see it in. Movies, music, phones… and with the company frequently touting the high number of iTunes accounts with a credit card stored, how long will it be before it gets into online payments?
Think about how much simpler it would be if buying anything online was as easy as buying music or apps on your iOS device - just choose the item and type in your password. Because you'd still need a payment card behind your iTunes account, it wouldn't so much be a competitor to the likes of Visa and Mastercard as it would to PayPal and Google Checkout.
Apple wouldn't be able to take a cut of the transactions anywhere near as high as its 30% on apps and music, but it wouldn't need to, since each payment would require almost no effort from them. We're already seeing the seeds of this idea in the EasyPay system in the Apple Store app. You can go into Apple Stores and pay for physical items by scanning them into the app and entering the password for your Apple ID.
As Apple continues to expand its server reliability and security, we're sure that in future years Apple will start expanding the number of places this service is offered.
6. Making Siri psychic
Siri continues to develop, with more searchable data being added and speech recognition being improved, but it has to be invoked to work - you have to bring Siri up and ask it what you want.
To be a truly useful virtual assistant, rather than a voice-command tool, it should anticipate your needs before you even know you need them. Google recently launched Google Now, which is a service very much along these lines. The idea is that you often want to know certain information at certain times or places, and your 'assistant' should be able to predict that.
First thing in the morning, you want to know the weather for the day. Just before the time you usually leave for work, you want to know about traffic problems or train delays. At 5pm on a Saturday, you probably want to know the football results. These examples are all of frequent activities, but it can also help with more unusual things you have scheduled.
Google Now doesn't just remind you when you've got an appointment, for example, but will also instantly bring up full directions for getting there, too. Passbook already does something similar by pulling live information into its entries - such as which gate you need to head to at the airport for your flight - but it's something that could be integrated into Siri and the Notification Center for really giving you instant information.
7. Storage improvements
We had been hoping that the iPhone 5 announcement would be the day that we finally saw a 128GB iPhone, but it remains beyond our grasp. More than that, the pitiful 8GB of storage in the iPhone 4 will be a real struggle to get by with if you want to download a lot of Universal apps, take lots of photos and video, and keep a good music collection on your phone (or even just two of those things).
The good news, then, is that Intel and Micron have jointly announced a new breed of flash memory chips that can fit 128GB into a single, fingernail-tip sized package. For devices where space is at a premium, including more than one flash memory chip (as would be necessary currently) might just take up too much room - especially in light of Apple's continuing quest to make its phones as thin as possible.
And the new design isn't just smaller; it's much faster, too. Intel says it should offer twice the performance of the previous designs, meaning that apps will install faster and games will load quicker when they open. Intel and Micron's new chips should already be entering mass production, and so will be available for future versions of the iPhone.
2016 - iPhone 7
1. Gesture and face recognition
Google recently introduced a 'face unlock' feature into Android, where rather than swiping or typing in a code to unlock your phone securely, it uses face detection to see if you're you, and unlocks accordingly. Similarly, Google owns a patent on using face detection as a method of switching users on a device - so if you're using an iPad, say, it might show a different set of apps and settings to if someone else was.
These technologies are somewhat imperfect at the moment, but they're exactly the kind of seamless simplicity Apple aims for in the iPhone. It might not be unlocking that the technology ends up in, though - it's possible that the iPhone could use your expression to determine if it's selecting the right option in autocorrect, for example - an involuntary frown from you, and it knows you didn't want to change 'were' to 'we're'.
Gesture control is an area that's come on hugely since Microsoft launched its Xbox Kinect controller, but it's still imperfect. With improved camera technology, it could be much more accurate and fine-grained, and again could be useful for the iPhone and iPad. A wave of your hand towards your phone could invoke Siri from a distance, for example, or there might be hand gestures for playback controls on a video, so you could pause it without having to to be within touching distance of your device.
Whether 3D technology ever makes it into the iPhone might depend on whether it continues to take off for movies and TV shows, and so whether Apple feels compelled to add it to the iTunes Store. If it does, you can be sure that it'll want a flagship device to show off the 3D imagery, and the iPhone is an ideal fit.
Because it's a device only one person uses, it can use technology similar to Nintendo's 3DS to let you see 3D without glasses. The way the 3DS works is to add a filter layer over the screen, which angles the direction of light from the pixels ever so slightly, directing half to the left eye and half to the right.
Improvements to the 3DS's technology in the short time since it was released mean that the 3DS XL model has a much larger 'sweet spot' than the original - that is, the area where you can hold your head to see the 3D effect fully is much more generous. This will become better still over time, and head-tracking could also help to keep the effect clean.
Of course, we've no doubt that Apple would allow you turn the 3D off, as you can on the 3DS. Adding a 3D screen wouldn't be the end of it, either; we'd expect to see a pair of high-quality cameras on the back of the screen for recording 3D movies, and two cameras on the front, for 3D FaceTime calls.
3. A more advanced screen
Apple has never been slow when it comes to adopting advanced screen technology, bringing in Retina displays on the iPhone and iPad well before its competitors were able to offer anything similar. But resolution is only half the battle - the new iPad's colour range and accuracy were just as important as its high resolution, while the iPhone 5's improved colour reproduction makes almost as big a difference as its added height.
For several years, OLED (organic light-emitting diodes) screens have been touted as the next big thing. A few issues - including difficulty in producing enough to fill demand - have held them back, but they've made a big impact in some Android phones. The important thing about them is that they don't require a backlight, unlike an LCD display currently used in the iPhone. This means they can be a good deal thinner, providing Apple with another way to reduce the size of the iPhone.
They also produce much deeper blacks than LCD screens, adding depth to movies. There's also anti-reflective technology to consider, making the iPhone easier to use outdoors. One kind of technology mimics the eyeballs of moths, using hexagons that are just nanometres in size to change the way light hits materials. Plus, improved construction processes and materials might make an edge-to-edge display possible in the future, reducing the width of the iPhone and letting it shed more weight.
4. Wireless charging
Apple's Phil Schiller was asked just after the iPhone 5 launch why it didn't include wireless charging capabilities, something that competitor Palm was offering back in 2009. Schiller said that wireless systems aren't that convenient, because you still need to plug a charging device into a wall, or another source of power. He suggested the humble USB cable was far more convenient.
There's no reason these two should be mutually exclusive, though, and we suspect that Apple will introduce wireless charging as soon as it thinks the technology is viable.
Inductive wireless charging works by using an electromagnetic field to transfer power from a charging station to an induction coil in the device that needs to be powered. Basically, you pop your phone on a pad that's plugged into a power socket, and it immediately starts charging. You can have larger pads that charge more than one device at a time, and you could have them dotted around the house.
At the moment, they suffer from poor efficiency compared to a cable - transferring around 70% of the power they consume, though this can be improved with higher-quality parts (which we'd expect from Apple).
There's a wireless charging standard called Qi that many companies use, which has the advantage that any Qi-certified charging station and device will work with each other. We hope that Apple will go down this flexible route, but it might well create its own wireless charging solution.
5. More advanced processors
For all of its impressive upgrade in terms of design, perhaps the iPhone 5's most ground-breaking addition is the A6 chip. Apple has been making its own branded processors for a few years, but they've been custom system-on-a-chip designs with fairly standard parts inside - Apple's been buying the same parts as everyone else, but putting them together into a package in its own way.
But that all changed with the A6: for the first time, the actual CPU itself is a custom Apple design. The basis of the A6 is reportedly the same as the A5 in the 4S, but Apple was able to bring out huge performance increases by altering the exact specifications - but that's actually quite old technology. It's likely that Apple is already working on a tweaked version of the newer technology, which will offer even more headroom for big leaps in speed.
It's not just the custom design that will benefit, though. Apple will be able to make the chips smaller than ever, built with a 22nm process instead of the current 32nm. This essentially means you make the same parts, but you make them smaller. You might think this would make them more expensive, but it actually works out cheaper because you use less material, and it makes them significantly more power efficient.
6. Developing iOS
As the iPhone becomes much more powerful, we'd expect iOS to grow and take advantage of what the hardware can do. We'd still expect apps to be at the core of everything you do in iOS rather than the operating system itself, and there are plenty of steps Apple can take to allow developers to create even more powerful apps.
The number of APIs available to developers will no doubt continue to grow, giving them more options for creating apps, and integrating Apple features. We hope to see more multitasking options; it may be that in a few years the iPad will have enough power to run apps concurrently in the same way that OS X does.
We'd also expect to see better ways to manage your apps - if you have lots, it's tough to manage them. With Spotlight and Siri, it's not too difficult to find an app if you don't know where it is on your Home screens, but this isn't a substitute for good organisation.
We also expect an API for Siri eventually, so that developers can allow it to access their apps, in much the way that it does for Reminders. We also hope that developers will be able to create Notification Center widgets like Apple's Weather widget. And though Apple continues to develop what web apps can do as an alternative to App Store apps, in the future we might see a feature like Gatekeeper on OS X, where you'd have the option of installing signed apps (meaning they've been verified by Apple) from outside the App Store.
7. Better batteries
Lithium-ion batteries have been powering our rechargeable devices for a long time, and the technology behind them has proven to be reliable. But it's by no means the best solution for portable power, and we don't need to reinvent things too drastically to see improvement.
There are two main possibilities for improving battery life, one of which involves making things very small. Nanowire batteries are a variant of current lithium-ion technology, using silicon nanowires in place of the graphite used in batteries at the moment. Silicon contains up to 10 times more lithium than graphite, so the energy density is increased, allowing for batteries with less mass. They should also be able to charge faster, due to a larger surface area. There are problems with the nanowires losing charge capacity over time, but solutions are being worked on.
The other option is batteries that use oxygen to generate electricity. Metal-air batteries oxidise a metal and then reduce the oxygen to generate current - a constant supply of air is needed for them to work, but the energy density is extremely high, and they're lightweight. It's only now that the materials to build them are viable, the problem being the choice of metal.
Lithium-air batteries offer the best energy density but are too delicate - problems occur if the battery's airflow gets humid – while zincair batteries offer good energy density, but struggle to retain capacity.