The concept of the modern navigator can be traced back to the early 1930s and the creation of the Iter-Auto. Manufactured by an Italian company based in Rome, the contraption was designed to be mounted to your car's dashboard and loaded with routes printed on long paper scrolls. It was hooked up to the vehicle's speedometer, and so the scroll would wind automatically in proportion with distance travelled. The maps themselves also included alerts of upcoming road features, like bridges and level crossings, as well as garages, hotels and such -- much like their digital equivalents today.

Diagrams from John J. Bovy's 1921 patent

But even the Iter-Auto wasn't an entirely new idea. A US patent granted in 1921 to one John J. Bovy describes a dashboard-mounted navigation aid for drivers that uses maps printed on scrolls. And a few years later, in 1927, a British firm manufactured the Plus Four Wristlet Route Indicator, which was like an early 20th century version of a smartwatch running Google Maps. It came bundled with scrolls covering many popular travel routes across the UK, often starting from London. You received a golf scorecard scroll, too, so you could say even this antique wristworn gadget had multiple 'apps.'

The Plus Four Wristlet Route Indicator

The key innovation of the Iter-Auto over previous, similar designs was the added level of automation. Thanks to its speedometer tether, it offered a new hands-free approach to roughly accurate navigation. The Iter-Auto proved to be ahead of its time, however. Car ownership was rare in the early '30s, and maps printed on scrolls were only really viable for routes along predominantly straight, Roman-style roads; a wrong turn, or any turn in fact, could quickly take you off-grid. As such, the Iter-Auto never achieved mass-market success.