From Sparks to Screens. Among the many narratives that trace the history of humanity, the one about invention is the most uplifting. Starting a million years ago with Homo erectus harnessing fire, invention has always accompanied humankind. On the list of globally transformative innovations, few can rival the smartphone.
When the first iPhone appeared in 2007, it was an expensive novelty, a gadget for the privileged few. Today, it has become a universal companion. No other object accompanies us as constantly or as intimately. We are inseparable from our smartphones.
A Planet of Smartphones. Smartphones are now found in nearly every hand and every corner of the world. Annual sales hover around 1.4 billion units (Figure 1), and about 68 percent of the global population owns one (Figure 2). Naturally, the penetration rate depends on a country’s wealth. In the United States, for example, 85 percent of adults own a smartphone, a higher share than those who brush their teeth twice a day (68 percent) or read at least one book a year (75 percent).
Even in low-income countries, adoption has been remarkable. In Ethiopia, 11 percent of people own a smartphone, a greater share than those with access to basic safely managed sanitation services (8 percent). The contrast is striking: in Qatar, access to such fundamental services is universal (100 percent), compared to 96 percent in Australia and 90 percent in France.
Glued to the Screen. We spend more and more time with our smartphones. They are our cameras, wallets, maps, and newsstands. They are the first thing we reach for in the morning and the last we touch at night. The average person now spends 4.5 hours a day looking at a smartphone (Figure 3). More than 60 percent of global internet traffic now comes from smartphones.
Living through Apps. What do we actually do on our smartphones? Roughly 90 percent of our smartphone use happens inside mobile apps. In other words, nearly four hours of daily human life are now mediated through applications. Communication, shopping, learning, banking, and dating all flow through mobile apps. At the beginning of this century, few people even knew what an “app” was. In 2010, the American Dialect Society chose “app” as its Word of the Year. Today, it is difficult to imagine a single day without them.
Mobile apps have quietly become the operating system of modern life. They are not just tools but gateways through which we act and connect. Many, if not most, human activities now involve apps in some essential way. The smartphone may be the hardware of our age, but apps are its software of being.
We no longer go online; we open an app. Apps structure our routines, shape our attention, and influence our decisions. They mediate how we work, learn, and socialize. In this sense, mobile apps are no longer accessories to life; they are life as we live it.
A New Era of Homo mobilis. A few years before COVID accelerated the integration of smartphones and mobile apps into daily life, during a subway ride in Miami, Konrad Grabiszewski and Alex Horenstein noticed something remarkable: every commuter except them was absorbed by a smartphone. The same scene unfolded on the streets, in restaurants, and, sadly, even in classrooms. Humanity was undergoing a profound transformation.
The smartphone has changed how people live. It is no longer just a device but part of who we are—an inseparable companion that shapes how we think, work, and connect. Mobile apps have become the medium through which we function. Imagine a day without your phone and your apps, and the challenge becomes clear.
Grabiszewski and Horenstein asked: What name should we give to this shift that has redefined daily life, social norms, and human behavior? At its core are mobile apps, which makes the adjective mobile especially fitting. The nature of this shift is global, rapid, and profoundly alters how humanity functions; essentially, it is both revolutionary and evolutionary. Hence, (R)evolution, a portmanteau combining both concepts.
Ultimately, humanity has entered a new era—the Mobile (R)evolution—with Homo mobilis as its protagonist. This observation led to a broader question: What does the Mobile (R)evolution mean for science in the twenty-first century?
The benefits of the Mobile (R)evolution for app developers are well known: fortunes have been made, and entire industries have emerged around mobile applications. But its impact reaches far beyond commerce, opening new horizons for scientific research. With smartphones in the hands of billions, the only real limit to what can be achieved in the pursuit of knowledge is the scientist’s imagination.
This new landscape has also changed the way research is done. A growing number of researchers are now creating apps designed for scientific inquiry. In this emerging approach, scientists become developers, translating their questions into code and turning smartphones into instruments of discovery.
Konrad Grabiszewski and Alex Horenstein pioneered the design, development, and execution of Blues and Reds, the first mobile experiment in the social sciences, marking the beginning of a new methodological paradigm. A mobile experiment is a study carried out entirely through a smartphone application, where users who download and play it become voluntary participants. Collectively, these devices form a distributed laboratory active across countries and time zones.
Mobile experiments are particularly powerful in the social sciences, including economics, psychology, marketing, and finance, where understanding human behavior in real contexts is essential, yet their potential reaches far beyond these fields. Smartphones already play crucial roles in healthcare research, road safety, coastal erosion monitoring, cognitive behavioral therapy delivery, water point tracking in arid regions, air pollution mapping, biodiversity surveillance, and many other areas of inquiry.
Designing mobile apps for science offers several important advantages.
Natural environment. For billions of people, apps are the setting of everyday decisions and interactions. A mobile experiment captures this reality directly. To study consumer behavior, a researcher might create an app that simulates a shopping experience; to study retail investors, an app functioning as a trading platform would achieve the same goal.
Continuous and rich data. Smartphones are equipped with an array of highly sensitive sensors that capture, among others, geolocation, movement, heart rate, and environmental cues with precision beyond human perception. Moreover, no other device remains with its user day and night as a smartphone does. This makes smartphones powerful yet unobtrusive instruments for continuous, objective monitoring of human behavior, physiological states, and environmental conditions, allowing scientists to collect data once inaccessible by any other method.
Global reach. The Mobile (R)evolution has reached almost every corner of the world. This allows researchers to access diverse participants and collect cross-cultural data with ease. Promotion of Blues and Reds and Escapisomo was carried out without the help of a professional agency and with a limited budget. Nevertheless, the experiments attracted participants from more than 140 and 180 countries, respectively, placing their reach between that of Coca-Cola (present in about 200 countries) and McDonald’s (in 114). No other research methodology can achieve such global participation with so few resources.
Sustainability. Data collection through apps requires no travel, buildings, or face-to-face contact. With almost no carbon footprint, mobile research ranks among the most sustainable scientific practices.
Citizen science. Anyone with a smartphone can contribute to research, strengthening public participation and scientific literacy. Mobile apps transform users from passive observers into active contributors, creating vast networks of volunteer citizen scientists. This democratization of science not only expands the scale of research but also fosters curiosity, trust, and engagement between scientists and society.
Apps created for science are transforming how knowledge is gathered and shared. They are redefining the very nature of research, making it open, global, and rooted in the real world. As mobile technology continues to evolve, its role in scientific discovery will only deepen.
What lies ahead for Mobile Science? Four directions are emerging, the first two are already steadily advancing, while the latter two remain more visionary.
1. Experiments with Human Subjects
Experimental research in the social sciences is entering a new era shaped by mobile technology. Mobile experiments open previously inaccessible frontiers of inquiry. Their global reach, continuous observation, and ability to generate rich, real-time data create opportunities that no other experimental methodology can match.
“Progress in science depends on new techniques, new discoveries, and new ideas, probably in that order.” — Sydney Brenner, Nobel Laureate in Physiology or Medicine
“New directions in science are launched by new tools much more often than by new concepts. The effect of a concept-driven revolution is to explain old things in new ways. The effect of a tool-driven revolution is to discover new things that have to be explained.” — Freeman Dyson, physicist and mathematician
Blues and Reds and Escapismo are early examples of this emerging approach. The former studies how people solve strategic problems, while the latter explores human decision-making and movement during emergency evacuations.
Of course, not every research question calls for a mobile experiment, nor should this approach replace other methods. Rather, mobile experiments complement laboratory experiments, field experiments, and online experiments, broadening the methodological toolkit and fostering a productive interplay between approaches to studying human behavior.
2. Healthcare and Medical Research
Healthcare is one of the most promising frontiers of Mobile Science. The ubiquity of smartphones, combined with the precision and diversity of the data they collect, is transforming how we detect, monitor, and prevent disease. What once required a visit to a clinic can now happen through a device in one’s pocket. For millions of people in regions with limited access to healthcare, this means that state-of-the-art medicine can reach them for the first time.
Central to this transformation is the emerging field of digital phenotyping, an approach for early diagnosis and proactive health management. It draws on active data (user input and interaction) and passive data (automatically collected signals) from smartphones and wearables to examine individuals’ behavioral, psychological, physiological, and environmental states.
This approach is already producing notable results. The project Sea Hero Quest, for example, used a mobile game to test navigational ability in more than four million participants worldwide. The data collected provided early insights into spatial disorientation, one of the first symptoms of Alzheimer’s disease, making it one of the largest dementia research efforts in history. Mobile apps have also been used for the detection and diagnosis of conditions including malaria, corneal ulcers, Parkinsonism, working memory deficiencies, atrial fibrillation, visual impairment, anemia, nasopharyngeal carcinoma, stress, depression, dry-eye disease, multiple sclerosis, and neurodevelopmental disorders.
The potential of Mobile Science extends far beyond individual diagnosis into the realm of public healthcare and the optimal allocation of resources. Imagine, for instance, a mobile application designed to detect a specific disease, perhaps in the form of a game or interactive task. Such an app identifies individuals who may be affected yet unaware of their condition or uncertain about where to seek medical help. At the individual level, it delivers crucial information — you may have a problem — and, when combined with digital nudging, can encourage users to seek professional care. This approach provides a low-cost and accessible pathway to early diagnosis.
At a broader scale, the same data can be aggregated into a real-time public health dashboard that maps disease prevalence and geographic distribution. These systems enable governments to identify emerging hotspots and allocate healthcare resources more effectively. Most public health dashboards are currently updated on a monthly or annual basis, which limits their usefulness for timely interventions. Mobile technology enables far more frequent updates. By continuously integrating user-generated data, such systems could make public health responses faster, more adaptive, and more equitable.
In this vision, mobile applications become a cornerstone of preventive medicine, enabling early detection, smarter resource allocation, and targeted behavioral guidance. The outcome is a more responsive, data-driven healthcare ecosystem in which prevention truly becomes the best cure.
3. Profiling and Predicting Behavior
Smartphones generate immense streams of behavioral data. Every tap, scroll, pause, and location signal contributes to an ever-expanding digital footprint. When aggregated across apps and contexts, these traces form a detailed map of human preferences, habits, and routines.
Such profiling naturally enables prediction. Algorithms can anticipate what people will buy, how they will vote, when they will exercise, or when they might choose to rest. For businesses, this creates opportunities to anticipate customer needs and personalize engagement with remarkable accuracy.
Yet the most consequential applications may lie in the public sphere. Government agencies concerned with safety and national security can use behavioral data to identify potential risks and intentions before harmful actions occur. Patterns of interaction within mobile apps, including games, can reveal early warning signs, allowing authorities to act preemptively. In this sense, mobile behavior analysis holds the potential not only to predict but also to prevent outcomes undesirable from a societal point of view.
4. Shaping Behavior
If prediction is about foresight, shaping behavior is about influence.
Mobile apps now have the ability to modify human behavior at scale. With billions of users carrying interactive screens in their pockets, small design choices such as notifications, interface layouts, timing, and tone can nudge millions simultaneously. At their best, these nudges promote positive change: greater physical activity, adherence to medical treatment, or more sustainable consumption.
At the same time, app design can also trigger behaviors with significant implications for public safety and national security. Consider trading apps. A seemingly minor adjustment in design can provoke panic selling or speculative bubbles among retail investors, while a shift in the emotional tone of a social feed can influence collective mood in a very short period. This raises an important question: what is the smallest change in a trading app’s design that produces the greatest harm, as measured by panic trading?
Smartphones are no longer passive observers of human behavior; they are active participants in shaping it. The next challenge for Mobile Science is to understand this power, apply it responsibly, and establish ethical boundaries for influence at scale.
