Design guidelines are a set of concepts and rules used to create an app's user interface. These define how the layout on-screen at any one time should be used to maximize the efficiency of presenting data to the user, as well as quickly informing them how to choose their next action. An app creator may look to other popular apps to determine how they have helped their users understand their app's purpose, either through the use of iconography or text highlighting. They may then want to use that inspiration to enable users of the inspiring app to easily use their own app. If many apps use the same visual cues, then future users will already be trained in their use when they discover them.
Similar to design guidelines, interaction patterns define how to implement app interactivity to maximize its efficiency. If a user can predict how the app will behave when they take a certain action, or be able to determine which action fits that which they want to achieve without experimentation, then an intuitive and rewarding experience will result.
In addition to purely physical actions such as button presses and accelerometer gestures, the virtual navigation flow should also be considered at the design stage. It should be intuitive for the user to move around the app screens to access the information or execute the commands as they would expect on a first guess. An easy way to achieve this is to use a menu with the items clearly labelling their associated actions. An alternative is to use explicit icons to inform the user implicitly of their purpose without needing to label them all.
Design guidelines and interaction patterns exist to help the developer help the user by ensuring user interface consistency across applications on the platform. It is often the case that the developer will have no problem operating their own watchapp because they have been intimately familiar with how it is supposed to work since its inception. When such an app is given to users, they may receive large amounts of feedback from confused users who feel they do not know if an app supports the functionality they though it did, or even how to find it. By considering a novice user from the beginning of the UI design and implementation, this problem can be avoided.
A Pebble watchapp experience is at its best when it can be launched, used for its purpose in the smallest amount of time, and then closed back to the watchface. If the user must spend a long time navigating the app's UI to get to the information they want, or the information takes a while to arrive on every launch, the app efficiency suffers. To avoid this problem, techniques such as implementing a list of the most commonly used options in an app (according to the user or the whole user base) to aid fast navigation, or caching remotely fetched data which may still be relevant from the last update will improve the user experience.
From an interaction pattern point of view, a complex layout filled with abstract icons may confuse a first-time user as to what each of them represents. Apps can mitigate this problem by using icons that have pre-established meanings across languages, such as the 'Play/Pause' icon or the 'Power' icon, seen on many forms of devices.
The main benefits of creating and following design guidelines and common interaction patterns are summarized as follows:
User interface consistency, which breeds familiarity and predictability.
Clarity towards which data is most important and hence visible and usable.
Reduced user confusion and frustration, leading to improved perception of apps.
No need to include explicit usage instructions in every app to explain how it must be used.
Apps that derive design from the system apps can benefit from any learned behavior all Pebble users may develop in using their watches out the box.
Clearer, more efficient and better looking apps!
Developers can use concepts and interaction patterns already employed in system apps and popular 3rd party apps to lend those affordances to your own apps. An example of this in mobile apps is the common 'swipe down to refresh' action. By using this action in their app, many mobile app makers can benefit from users who have already been trained to perform this action, and can free up their app's UI for a cleaner look, or use the space that would have been used by a 'refresh' button to add an additional feature.
In a similar vein, knowing that the Back button always exits the current
Window in a Pebble app, a user does not have to worry about knowing how to
navigate out of it. Similarly, developers do not have to repeatedly implement
exiting an app, as this action is a single, commonly understood pattern - just
press the Back button! On the other hand, if a developer overrides this action a
user may be confused or frustrated when the app fails to exit as they would
expect, and this could mean a negative opinion that could have been avoided.
Read Core Experience Design to learn how design guidelines helped shape the core Pebble system experience.