The next billion users will virtually all be on mobile
This presents unique challenges for web developers who must abandon the limited mobile first approach in favor of a comprehensive mobile strategy.
You can address these challenges by focusing a few key areas listed below.
Design for seamless connectivity
Low bandwidth and intermittent connectivity are the norm for many people accessing the web. Most people online still have 2G connections or "3G" that downgrades to 2G. Even by 2020, more than 10% of users will still be on 2G. Many smartphones are used offline, and users regularly turn on airplane mode to avoid data consumption.
Conserve data usage
High data cost is often a greater barrier to access than poor connectivity. Mobile users are cost-conscious; even "unlimited" plans can become expensive when roaming or if unexpected fees are applied. Many mobile users are extremely cost conscious, with good reason: for example, a 500MB data plan in India costs the same as 17 hours of minimum wage work.
Reduce battery consumption
Many people, even in urban areas, don't have access to a reliable and affordable power supply. This makes power conservation a critical factor in all app and content design.
Optimize for device capability
Low spec is the norm. Globally, most new internet users have low-cost devices with basic hardware: single-core processors, 4" screens, limited memory, and limited storage.
Build multi-device content
Large-layout, graphics-heavy content frustrates users and discourages them from using your app or site. Content that is too wide or too tall is overlooked by some users and deliberately avoided by others — and excess content adds page weight and data cost.
Transactions & monetization: think global
Payment systems are inaccessible for many people on the web. Many users globally don't have bank accounts and don't use credit cards — including 8% of US households. Many payment systems don't work well on small viewports or with unreliable connectivity.
Plan for localization
Localization can help you access new markets. Many websites are only published in English, but English is not the first language of most people online. Only 5.52% of the world's population are native English speakers and US or European cultural conventions may not be familiar or intuitive. Instructions or prompts that are succinct and compact in English may be verbose and obtrusive in other languages.