How did smartphones go from luxury gadgets to essential tools in just 15 years?

The answer

The smartphone revolution began with IBM's Simon in 1994 (the first phone with a touchscreen and apps), but exploded with Apple's iPhone in 2007, which combined a phone, music player, and internet browser with an intuitive multi-touch interface. The creation of app stores in 2008 transformed phones into platforms for millions of third-party applications. Today, over 6.8 billion people use smartphones - roughly 85% of the world's population - and these devices have replaced cameras, maps, wallets, newspapers, and alarm clocks.