Mobile app development is a complex activity which reunites several specialties, from corporate identity guidelines to coding and graphic design. Leaving aside the required customizations for each individual company, which aligns the mobile app with all the other brand elements, a well-built mobile app consists of two interdependent key elements: user experience (UX) and user interface (UI).

Interdependent, but Competing

If we start polling mobile app designers, we will certainly find a great rift between two groups of thought: that which believes that UX is the most important element in a mobile app, and that which believes that UI is king. What motivates this different way of perceiving the order and importance of two key elements, which cannot exist one without the other, in the structure of a great looking and functioning mobile app?

Possibly, it all depends on what is considered the most important function of the app, and this kind of thinking was created by prior experience working on apps for clients with specific expectations. For many designers and their end clients, the way a mobile app looks, the smooth and seamless display of animations, vivid colors and transition effects, are the top priorities. This is a residual opinion from the early days of mobile apps, when they represented a novelty and they only needed to look great to become popular.

The new school of thinking among mobile app development specialists states that the most important function of its app is its usability. The reason apps exist, these specialists argue, is to improve the way people interact with brands and corporations, to facilitate their access to information, entertainment and shopping opportunities.

Who is right among these two groups? In order to reach a possible conclusion, we need to analyze the features and goals of each of these two key elements.

What Is UI and How Is It Achieved?

User interface is first and foremost responsible with the way a certain app looks and feels to the user. The UI designer has to take into account the specific visual identity guidelines provided by the client and analyze the behavior patterns of the customer personas developed by the marketing team.

Therefore, a mobile app with great UI is the one which is in line both with the brand identity and with the expectations of the target customers. The color palette, the range of animations and transitions, the degree of customization and interaction which the user is allowed to make within the app... all these pertain to user interface. In this respect, the UI can be perceived as the “packaging” of a mobile app, designed to gain the user’s attention and interest.

What Is UX and What Does It Consist Of?

User experience is the way an app works and gives people the response they are expecting when interacting with it. Great UX involves first and foremost, a high level of compatibility with different mobile phone specifications such as hardware and size of screen. For example, on a mobile phone with a large screen (five inches or more), placing a frequently used button in the top left corner makes it very difficult to reach by the user with just one hand. The obvious placement for this button in order to ensure great user experience is in the bottom left corner, where the user can easily tap on it with their thumb.

Therefore, user experience consists of a series of specialties, such as coding and testing for compatibility, and this should be taken into consideration from the initial phase of discussion about the building of the mobile app. It is the backbone of any kind of online or mobile tool developed for an audience, because it is the key justification of its existence: to serve a purpose, to solve a problem, and to satisfy a need of communication and interaction.

Not a Conclusion, But an Opinion

Great mobile apps are those which are constantly useful to people. These apps save time and facilitate communication, shopping and other kind of interactions which people want to have with a business. They are easy to use and provide the user with the perception of having everything they need for establishing this communication at their fingertips in a great looking, compact and seamlessly working tool.

Therefore, both UI and UX are critical, and none of these can be given a greater importance than the other. A good looking app which loads slowly and has lags in working with it will be discarded, no matter how advanced and pleasant its graphics are. On the other hand, an app which works well but is packaged in clumsy, old-fashioned and unresponsive design will also be quickly uninstalled by users.

The true key to developing a professional and successful mobile app is, therefore, finding the perfect balance between UX and UI, and making it visible in the way the app looks and works.