Final answer:
Apps are an essential feature of smartphones, providing convenience and cost savings with cheaper calls and data services, as well as enabling important technologies like internet calling and video conferencing.
Step-by-step explanation:
Apps are considered an important feature of smartphones due to the convenience and cost savings they offer to consumers. With the evolution of technology, improvements have led to cheaper, faster, and better-quality data transmission, along with spin-off technologies like free Internet-based calling and video calling. These features provide more consumer choice, reduce costs for phone calls (especially long-distance ones), and improve phone service quality.
Moreover, in developing countries, smartphones have enabled people to bypass traditional stages of infrastructure development, assisting in areas like banking and accessing educational resources through the internet, hence transforming lives significantly.