With the upcoming launch of Apple Watch next month, developers are undoubtably thinking about ways of adapting their current apps and potentially new apps for the smaller screen. This exercise is similar in many ways to the adaptation of desktop apps to mobile apps, which resulted in many confusing, complicated, and frustrating first generation mobile ports. I thought it would be interesting to focus on some of the unique differences of Apple Watch and the impact that these differences will have on the types of apps and user interfaces that will emerge over the next few years.

1. Smaller touch screen = more swipes + gestures and fewer taps

At 1.6″, the Apple Watch screen is certainly tiny compared to current mobile devices. As you shrink the size of a touch screen, you require users to pay closer attention to their tap locations and touch interactions. Steve Jobs once famously said you would need to “sand down your fingers” to use a 7″ tablet, and the same sentiment holds true for the 1.6″ display.  What this means is that touching different locations of the display precisely will be more of a mental and physical exercise than it currently is on mobile phones.

Swipes and other touch gestures, on the other hand, do not need either a large area or a precise location. As a result, the best watch apps will employ swipes and gestures for UI control rather than buttons that require specific touch locations.

2. Location almost) doesn’t matter

On a smartphone, if you are using and holding the device with one hand, there are hard-to-reach regions requiring a two handed operation. This has resulted in a general mobile UI paradigm to place important UI elements at the bottom of the screen (where it is easier to reach) and rarely used elements at the top (where it is hardest to reach). For a small watch screen, that’s not an issue. The main consideration about UI placement is blockage of the screen, most likely resulting in UI elements and buttons that are towards the outer edges of the device.

3. The need for smart information filters

Apple Watch, more than anything else, is an information consumption device that allows for quick glances of messages, emails, and other notifications. Today, most notifications are ignored since we do not check our phones every second, and when we do, we usually see a collection of notifications. With a watch, it is easy to flick your wrist whenever there is a notification. This will create a need for better filtering of notifications so that we only get the ones we truly care about. Extending this idea to news and alerts, information filtering will be critical for a watch, and the importance level of those alerts will vary depending on the situation we are in.

4. Motion gestures and voice

It is impossible to use a mobile device today without at least one hand holding the device.  You could also argue that one of the biggest drawbacks of a watch is the need for two handed operation (one hand to turn it towards you, another to control the screen). However, if single-handed motion gestures (i.e. flicking of the wrist to turn the screen on) and voice control become accurate enough, that would be a game changer for how we use the watch (by enabling almost hands-free operation). I would expect to see a new breed of apps that rely solely on wrist motions for controlling app flow. This, of course, cannot work for every single app, but for a large number of focused apps, it would be the ideal interface.

5. New types of apps

We know (or have been told) that Apple Watch will be great for getting notifications and for communicating via emojis. We expect that getting notifications on our wrists will save time over taking out our phones (although this is questionable, as we will discuss shortly). But what are the killer apps for Watch? What are some applications that could not exists without the device?

As a secondary display, the watch can serve a useful purpose. One example that we have been exploring is using Apple Watch as the viewfinder of the iPhone’s camera, which has applications for seeing regions of your skin that you currently cannot, or using the iPhone as a quickly deployed security camera. But applications like this are just the start. Apple Watch hais significant potential for data collection as an always-on medical recorder, one that can track and store your health habits and (eventually) help with medical diagnoses.

But is Apple Watch any good for editing spreadsheets, or editing a document? The initial answer seems to be no, though just as was the case with mobile, developers will likely find clever user interfaces for performing many tasks on a watch that may seem impossible today.

6. From desktop to mobile to watch

In the early days of the iPhone, many developers were rushing to port their desktop apps to the phone. The result was not always ideal, and throughout the past seven years we have seen a large share of apps with complex UI that were based on a desktop mindset. The same will be true for Watch.

For the desktop, you could have a large collection of tiny buttons, since real estate was easily available and you could use a mouse to click on them. For mobile, our finger sizes provided a lower limit on the size of buttons and real estate is scarce, resulting in larger buttons for often-used tasks and secondary menus for rarely-used tasks.  Watch, with its extremely limited real estate, will require an equally different type of thinking. For example, the digital crown (the dial on the side of the watch) will be used much more heavily for UI since it is easy to control and does not cover the screen. Also, whereas from desktop to mobile we went from hundreds of buttons to just a handful, from mobile to Watch will reduce the number of touch buttons to just a few (at most). This will mean more pages or modes for apps, and overall very lightweight and focused applications.

7. Time (not) saved

It has been reported that Apple Watch saves time by reducing the need to pull out our phones, unlock them, and swipe to read notifications. But is this really the case? On a typical day, a typical mobile user might check their phone every 5 minutes for about 16 hours. That would mean a total of 192 repetitions of pulling out a phone (about 2 seconds), unlocking (about 1 second), and eventually putting the phone back (about 2 seconds).  That would mean the total time during the day spent on these tasks is 16 minutes! And if you check your phone less often (every 10-15 minutes), and are quicker on the draw, you are spending only 5 minutes a day on these tasks. It is hard to argue that saving 5 minutes per day is life changing.

The time saved will truly matter when the actual actions we do on our phone can be done faster on Watch. For example, if we could see only a subset of notifications or emails that mattered, that would save us a significant amount of time that would normally have been spent reading emails/notifications and filtering them ourselves. Information filtering is a key benefit for Watch, and most content-heavy apps need to account for information priority (and sometimes allow the user to manually control the priority setting). But because the watch is always there, interaction with Watch apps need to be efficient and quick. If we had hours for desktop apps and only a few minutes for mobile apps, the ideal interaction time for Watch apps should be on the order of a few seconds.

8. Text entry

Watch is useless unless you can enter information into it.  Emoji’s, free-form drawing, and voice control are useful first steps. But if there was a good way of entering text to quickly respond to messages and emails, that would make the device far more useful. Obviously, a standard QWERTY keyboard is out of the question given the size of the watch. But, there are some alternatives that could actually work well (including two of my favorites, Fleksy and Minuum). Once typing on Watch becomes practically doable, this will substantially increase the number and type of applications that can work with the device.

My guess is that Apple is well aware of the need to enter text information on the watch. I wouldn’t be surprised if the company acquired some of the current software keyboard companies, if it hasn’t already. I have yet to see a gesture-based or probabilistic keyboard on a watch that I would use on a daily basis, but there are solutions that are almost there.

Overall, it will be interesting to see how developers adapt to Apple Watch and how adoption of the device will eventually transform the iPhone itself.

Parham Aarabi is founder and CEO of ModiFace and a professor of electrical and computer engineering at the University of Toronto, where he teaches a graduate course on Advanced Mobile User Interfaces.