June 29, 2017 11:15 AM EDT

Apple’s indelible first iPhone went on sale 10 years ago on June 29, changing how we relate to our phones forever. It established the parameters for what a modern smartphone ought to be, ushering in an era since defined by ubiquitous touchscreens and libraries of easily obtained apps.

It’s also undergone dramatic design upheavals since 2007. It’s easy to forget that the original model didn’t have an App Store. Its touchscreen was a mere 3.5-inches with 480-by-320 pixel resolution — tiny compared to the roomy, high-resolution displays we take for granted today. But today’s iPhones didn’t get there overnight.

To mark the iPhone’s 10th anniversary, here’s an outline of its biggest milestones, and how a device that’s garnered over a billion in cumulative global sales evolved over time.

Read more: This Is Why the iPhone Upended the Tech Industry

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